Experimental Study of Erosion Wear in a
氧化铝陶瓷多粒子冲蚀磨损的数值模拟
氧化铝陶瓷多粒子冲蚀磨损的数值模拟∗胡彪;纪秀林;段慧;丁伟【摘要】采用LS⁃DYNA有限元分析软件建立多粒子冲蚀氧化铝陶瓷的有限元模型，运用LS⁃DYNA求解器对冲蚀过程进行仿真，通过观察靶材等效应力的分布分析冲蚀机制。
结果表明：靶材体积磨损率随着冲蚀角度的增大而增大，在冲蚀角度达到90°时，体积磨损率达到最大值，表现出典型的脆性材料的冲蚀特性；靶材的体积磨损率随着冲蚀速度的增大而增大，且具有良好的线性增长关系；靶材的体积磨损率整体上随着冲击粒子粒径的增大而增大，但在达到临界尺寸的一段时间内会随着粒径的增大而减小；靶材会吸收粒子的一部分动能转化为自己的内能，但随着粒子冲击结束而离开靶材表面，靶材表面形成微裂纹以及部分单元失效，因此靶材的能量随着单元的失效而减小。
%LS⁃DYNA was used to establish the finite element model of multi particles impacting on alumina ceramics, and the erosion process was simulated by using LS⁃DYNA solver� The erosion mechanism was analyzed by observing the distribution of Von Mises stress of the target� The results show that volume loss rate of the target is increased with increas⁃ing the impact angle, and volume loss rate reaches the maximum value at the impact angle of 90°, which exhibits erosio n characteristics of typical brittle materials� Volume loss rate of the target is increased with increasing the impact velocity, and they have good linear growth relationship� Volume loss rate of the target is increased with increasing the impact parti⁃cle size as a whole, but it is decreased within a period of time when the impact particle size reaches a critical size� The target absorbs part of the particles kinetic energy and transforms it intointernal energy, and when the particles leave the target surface,micro⁃crack and some elements failure are formed on the target surface, therefore, the target total energy is decreased with the failure of the elements.【期刊名称】《润滑与密封》【年(卷),期】2015(000)004【总页数】5页(P49-53)【关键词】冲蚀磨损;氧化铝陶瓷;脆性材料;多粒子;冲蚀机制【作者】胡彪;纪秀林;段慧;丁伟【作者单位】河海大学常州校区机电工程学院江苏常州213022;河海大学常州校区机电工程学院江苏常州213022;河海大学常州校区机电工程学院江苏常州213022;河海大学常州校区机电工程学院江苏常州213022【正文语种】中文【中图分类】TH117.1冲蚀磨损是固体颗粒随着高速流体对材料表面冲击造成的材料损坏，是一个动态的失效过程[1]。
大学英语四级考试试题真题 (3)
大学英语四级考试试题真题PartⅠ Listening Comprehension (20 minutes)Section ADirections:In this section,you will hear 10 short conversations.At the end of each conversation,a question will be asked about what was said.Both the conversation and the question will be spoken only once.After each question there will be a pause .During the pause,you must read the four choices marked A),B),C)and D),and decide which is the best answer.Then mark the corresponding letter on the Answer Sheet with a single line through the centre.Example: You will hear:You will read:A)At the office B)In the waiting roomC)At the airport D)In a restaurantFrom the conversation we know that the two were talking about some work they had to finish in the evening.This is most likely to have taken place at the office.Therefore,A)"At the office"is the best answer.You should choose [A] on the Answer Sheet and mark it with a single line through the centre.Sample Answer [A][B][C][D]1.A)A math teacher and his colleague. B)A teacher and his student.C)A student and his classmate D)A librarian and a student2.A)Tony could not continue the experiment B)Tony finished the experiment last night.C)Tony thought the experiment was well done. D)Tony had expected the experiment to be easier.3.A)She can't put up with the noise. B)She wants to save money to buy a piano.C)The present apartment is too expensive. D)She has found a job a neighbouring area.4.A)He is not very enthusiastic about his English lessons.B)He has made great progress in his English.C)He is a student of the music department.D)He is not very interested in English songs.5.A)At home. B)In a restaurant. C)In a car D)On the street.6.A)His injury kept him at home. B)He didn't think it necessary.C)He was too weak to see the doctor. D)He failed to make an appointment.7.A)5:15 B)5:10 C)4:30 D)5:008.A)The man needs help. B)The man is complaining.C)The man likes his job. D)The man is talking with his boss.9.A)Wear a new dress. B)Make a silk dress. C)Attend a party D)Goshopping.10.A)He played his part quite well. B)He was not dramatic enough.C)He proformed better than the secretary D)He exaggerated his part. Section B Compound Dictation注意:听力理解的B节(Section B)为复合式听写(Compound Dictation),题目在试卷二上,现在请取出试卷二.Part ⅡReading Comprehension (35 minutes)Directions: There are 4 passages in this part Each passage is followed by some questions or unfinished statements.For each of them there are four choices marked A),B),C)and D).You should decide on the best choice and mark the corresponding letter on the Answer Sheet with a single line through the centre.Passage OneQuestions 11 to 15 are based on the following passage.People living on part of the south coast of England face a serious problem.In 1993,the owners of a large hotel and of several houses discovered,to their horror, that their gardens had disappeared overnight.The sea had eaten into the soft limestone cliffs on which they had been built.While experts were studying the problem.the hotel and several houses disappeared altogether,sliding down the cliff and into the sea.Erosion(侵蚀)of the white cliffs along the south coast of England has always been a problem but it has become more serious in recent years.Dozens of homes have had to be abandoned as the sea has crept farther and farther inland.Experts have studied the areas most affected and have drawn up a map for local people,forecasting the year in which their homes will be swallowed up by the hungry sea.Angry owners have called on the Government to erect sea defenses to protect their ernment surveyors have pointed out that in most cases ,this is impossible .New sea walls would cost hundreds of millions of pounds and would merely make the waves and currents go further along the coast ,shifting the problem from one area to another.The danger is likely to continue ,they say ,until the waves reach an inland area of hard rock which will not be eaten as limestone is .Meanwhile,if you want to buy a cheap house with an uncertain future,apply to a house agent in one of the threatened areas on the south coast of England.You can get a house for a knockdown price but it may turn out to be a knockdown home.11.What is the cause of the problem that people living on parts of the south coast of England face?A)The rising of the sea level.B)The experts'lack of knowledge.C)The washing-away of limestone cliffs.D)The disappearance of hotels,houses and gardens.12.The erosion of the white cliffs in the south of England________.A)will soon become a problem for people living in central EnglandB)has now become a threat to the local residentsC)can be stopped if proper measures are takenD)is quickly changing the map of England13. The experts study on the problem of erosion an ______A)warn people whose homes are in dangerB)provide an effective way to slow it downC)help to its eventual solutionD)lead to its eventual solution14. It is not feasible to build sea defenses to protect against erosion because ________ .A)house agents along the coast do not support the ideaB)it is too costly and will endanger neighboring areasC)the government it too slow in taking actionD)they will be easily knocked down by waves and currents15. According to the author, when buying a house along the south coast of England, people should _______ .A)take the quality of the house into considerationB)guard against being cheated by the house agentC)examine the house carefully before making a decisionD)be aware of the potential danger involvedPassage TwoQuestions 16 to 20 are based on the following passage.Sport is not only physically challenging, but it can also be mentally challenging. Criticism from coaches, parents, and other teammates, as well as pressure to win can create an excessive amount of anxiety or stress for young athletes(运动员). Stress can be physical, emotional, or psychological and research has indicated that it can lead to burnout. Burnout has been described as dropping or quitting of an activity that was at one time enjoyable.The early years of development are critical years for learning about oneself. The sport setting is one where valuable experiences can take place. Young athletes can, for example, learn how to cooperate withothers, make friends, and gain other social skills that will be used throughout their lives. Coaches and parents should be aware, at all times, that their feedback to youngsters can greatly affect their children. Youngsters may take their parents' and coaches' criticisms to heart and find a flaw (缺陷) in themselves.Coaches and parents should also be cautious that youth sport participation does not become work for children. The outcome of the game should not be more important than the process of learning the sport and other life lessons. In today's youth sport setting. Young athletes may be worrying more about who will win instead of enjoying themselves and the sport. Following a game many parents and coaches focus on the outcome and find fault with youngsters' performances. Positive reinforcement should be provided regardless of the outcome. Research indicates that positive reinforcement motivates and has a greater effect on learning than criticism. Again, criticism can create high levels of stress, Which can lead to burnout.16. An effective way to prevent the burnout of young athletes is ______A)to reduce their mental stress C)to make sports less competitiveB)to increase their sense of success D)to make sports more challenging17. According to the passage sport is positive for young people in that ____ .A) it can help them learn more about societyB) it enables them to find flaws in themselvesC) it can provide them with valuable experiencesD) it teaches them how to set realistic goals for themselves18. Many coaches and parents are in the habit of criticizing young athletes ______ .A)believing that criticism is beneficial for their early developmentB)without realizing criticism may destroy their self confidenceC)in order to make them remember life's lessonsD)so as to put more pressure on them19. According to the passage parents and coaches should _____________ .A)pay more attention to letting children enjoy sportsB)help children to win every gameC)train children to cope with stressD)enable children to understand the positive aspect of sports20. The author's purpose in writing the passage is ____________ .A)to teach young athletes how to avoid burnoutB)to persuade young children not to worry about criticismC)to stress the importance of positive reinforcement to childrenD)to discuss the skill of combining criticism with encouragementPassage ThreeQuestions 21 to 25 are based on the following passage.Humanity uses a little less than half the water available worldwide. Yet occurrences of shortages and droughts (干旱) are causing famine and distress in some areas, and industrial and agricultural by-products are polluting water supplies. Since the world's population is expected to double in the next 50 years, many experts think we are on the edge of a widespread water crisis.But that doesn't have to be the outcome. Water shortages do not have to trouble the world-if we start valuing water more than we have in the past. Just as we began to appreciate petroleum more after the 1970s oil crises, today we must start looking at water from a fresh economic perspective. We can no longer afford to consider water a virtually free resource of which we can use as much as we like in any way we want.Instead, for all uses except the domestic demand of the poor, governments should price water to reflect its actual value. This means charging a fee for the water itself as well as for the supply costs. Governments should also protect this resource by providing water in more economically and environmentally sound ways. For example, often the cheapest way to provide irrigation(灌溉)water in the dry tropics is through small-scale projects, such as gathering rainfall in depressions(凹地) and pumping it to nearby cropland.No matter what steps governments take to provide water more efficiently, they must change their institutional and legal approaches to water use. Rather than spread control among hundreds or even thousands of local, regional, and national agencies that watch various aspects of water use, countries should set up central authorities to coordinate water policy.21. What is the real cause of the patential water crisis.A)Only harf of the world's warter can be used.B)The world population is inereasing faster and faster.C)Half of the world's water resources have been seriously polluted.D)Humanity has not placed officient value on water resources.22. As indicated in the passage, the water problem _________ .A)is already serious in certain parts of the world.B)Has been exaggerated by some experts in the fieldC)Poses a challenge to the technology of building reservoirsD)Is underestimated by government organizations at different levels23. According to the author, the water price should _______ .A)be reduced to the minimumB)stimulate domestic demandC)correspond to its real valueD)ake into account the occurrences of droughts24. The author says that in some hot and dry areas it is advisable to _________ .A)build big lakes to store waterB)construct big pumping stationsC)build small and cheap irrigation systemsD)channel water from nearby rivers to cropland25. In order to raise the efficiency of the water supply, measures should be taken to ______ .A)guarantee full protection of the environmentB)centralize the management of water resourcesC)increase the sense of responsibility of agencies at all levelsD)encourage local and regional of water resourcesPassage FourQuestions 26 to 30 are based on the following passage.We can see how the product life cycle works by looking at the introduction of instant coffee. When it was introduced, most people did not like it as well as "regular"coffee and it took several years to gain general acceptance (introduction stage). At one point, though, Instant coffee grew rapidly in popularity and many brands were introduced (stage of rapid growth). After a while people became attached to one brand and sales leveled off (stage of maturity). Sales went into a slight decline （衰退）when freeze-dried coffees were introduced (stage of decline).The importance of the product life cycle to marketers is this: Different stages in the product life cycle call for different strategies. The goal is to extend product life so that sales and profits do not decline. One strategy is called market modification. It means that marketing managers look for new users and market sections. Did you know, for example, that thebackpacks that so many students carry today were originally designed for the military?Market modification also means searching for increased usage among present customers or going for a different market, such as senior citizens.A marketer may re-position the product to appeal to new market sections.Another product extension strategy is called product modification. It involves changing product quality, features, or style to attract new users or more usage from present users. American auto manufacturers are using quality improvement as one way to recapture world markets. Note, also, how auto manufacturers once changed styles dramatically from year to year to keep demand from falling.26. According to the passage, when people grow fond of one particular brand of a product, its sales will ____ .A)decrease gradually C)improve enormouslyB)become unstable D)remain at the same level27. The first paragraph tells us that a new product is _____ .A)usually introduced to satisfy different tastesB)often more expensive than old onesC)often inferior to old ones at firstD)not easily accepted by the public28. Marketers need to know which of the four stages a product is in so as to __________ .A)work out marketing policies C)promote its productionB)increase its popularity D)speed up its life cycle29. The author mentions the example of "backpacks"(Line 4, Para.2 ) to show the importance of _______ .A)increasing usage among students C)pleasing the young as well as the oldB)exploring new market sections D)serving both military and civil needs30. In order to recover their share of the world market, U.S. auto makers are _______ .A)improving product quality C)re-positioning their product in the marketB)modernizing product style D)increasing product features。
基于fluent的泥浆脉冲发生器冲蚀磨损规律研究
change of the flow area to change the mud pressure in the drill pipe. Its main components are composed of stator and rotor.
When the liquid passes through the mud pulse generator, it will lead to the alternating change of the flow area of the tool,
对工具的冲蚀磨损率会递减，最终趋于稳定；定子的倾斜角约为15°时，冲蚀磨损对工具的影响较小。
关键词：泥浆脉冲发生器; 冲蚀磨损; 定转子间隙; 工具倾斜角; Fluent
中图分类号:TE 922
文献标志码:粤
文章编号：员园园圆原圆猿猿猿（圆园20）02原园026原园4
Study on Erosion and Wear Law of Mud Pulse Generator Based on Fluent
thus forming a continuous pressure pulse. When drilling fluid passes through mud pulse generator, because of the faster
flow rate of drilling fluid, there will be obvious turbulence phenomenon. Based on the theory of solid-liquid two-flow and
1 泥浆脉冲发生器数值模拟
1.1 几何模型
通过建立泥浆脉冲发生器冲蚀几何模型进行数值仿
2000-2010年硕士毕业论文中英文目录汇总2010年
2000-2010年硕士毕业论文中英文目录汇总2010年序号姓名导师硕士论文题目学科、专业毕业时间（年）1.高素娟黄明斌王占礼黄河中游多沙粗沙区坡面土壤侵蚀动力学过程试验研究Experimental Study of Dynamic Processes of SoilErosion on Hillslope in the Coarse Sediment Regionof the Yellow River Middle Reaches环境科学20102.王浩王文龙黄土高塬沟壑区沟坡道路侵蚀特征及植物路防蚀机理研究Experimental study on hydrodynamic characteristics ofearth road erosion and the mechanism of plant-coveredroad reducing the road erosion on the Loess Plateau土壤学20103.王卫锋张岁岐ZmPIPs在玉米幼苗短期水分胁迫及复水中的生理作用The physiological roles of ZmPIPs in young maizeresponses to short term water stress and rewater植物学20104.吴妍张岁岐水分胁迫及复水条件下外源Ca2+对玉米幼苗根系吸水能力的影响Effect of Calcium on Water Uptake by Root of MaizeSeedling under Water Stress and Rehydration Conditions植物营养学20105.陈玉华张岁岐不同栽培模式对旱作冬小麦根系生长及水分利用的影响Effect of Different Cultivation Patterns on Root Growthand Water Use of Winter Wheat in Dryland生态学20106.聂朝娟邓西平花后水分亏缺对不同生态型小麦光合特性和蔗糖代谢的影响Effect of water deficit on photosynthetic characteristicsand sucrose metabolism of different varieties wheat afteranthesis生态学20107.陈炜邓西平不同栽培模式下旱地小麦灌浆过程中同化物转运的研究Effect of different cultivating models on the assimilatetranslocation in dryland wheats植物学20108.伍小兵邓西平H2O2 对甘薯幼苗不定根的生长和植株抗冷性的影响Effect of H2O2 on the adventitious root growth andchilling resistance of sweetpotato seedlings植物学20109.黄洁李世清栽培条件对作物生长及根系提水作用的影响Effects of different growth conditions on plant groeth androot hydraulic lift生态学201010.宋淑英李世清不同供氮水平小麦/玉米幼苗生理特性对CO2浓度倍增的响应Responses of physiological characteristics of wheat/maizeseedling to elevated co2 concentration植物营养学201011.汪羽宁李世清控制灌溉的土壤水分探头合理埋设深度研究Sensor Placement for Precise Irrigation Scheduling Using植物营养学2010Soil Moisture Information12.王佩玲李世清CO2浓度倍增与介质施氮对冬小麦物质生产及氮素利用的影响Effects of CO2 concentration elevation and nitrogenapplication on dry matter production and nitrogenutilization in winter wheat生态学201013.邢顺林李世清青藏高原与黄土高原土壤氮素矿化过程对温度变化响应的比较研究Comparative Study of Qinghai-Tibet Plateau and LoessPlateau Soil Nitrogen Mineralization Process Response toTemperatures Change生态学201014.徐洪敏李世清栽培模式对黄土高原南部旱作春玉米干物质累积及水、氮利用效率的影响Effects of different cultivation management practices ondry matter accumulation and water-nitrogen utilizationefficiency of spring maize on the Loess Plateau植物营养学201015.王禹杨明义137Cs和210Pbex复合示踪研究东北黑土区坡耕地土壤侵蚀速率Investigating the Soil Erosion Rates on the CultivatedSlopes in the Northeast Black Soil Region of China Using137Cs and 210PbexMeasurements土壤学201016.刘远利郑粉莉WEPP型（坡面版）在东北黑土区的适用性评价Assessment onWEPPModel (Hillslope Version)Applicability to the Black Soil Region in NortheastChina地图学与地理信息系统201017.余叔同郑粉莉黄土丘陵区坡沟系统沟蚀发育过程模拟与可视化Simulation and Visullization of gully erosion developmentprocess in hillyslope-gully system of loess hilly region地图学与地理信息系统201018.郭晓清郑粉莉陕西省土地荒漠化动态变化及其防治管理信息系统Dynamic change of land desertification And it’scombatting management Information system in shaanxiprovince地图学与地理信息系统201019.陈吉强郑粉莉黄土坡面沟蚀发育过程的模拟试验研究An experimental study on loessial hillslope gully erosiondevelopment process地图学与地理信息系统201020.李国辉安韶山郑粉莉黄土丘陵区典型植物根际与非根际土壤性质差异的比较研究A comparative study on the differences of soil Propertiesbetween rhizosphere and Non- rhizosphere of typical plantIn the loess hilly region水土保持与荒漠化防治201021.张博闻邵明安原油在土壤中入渗的试验研究Experiment on crude oil infiltration Into soils环境科学201022.赵梅邵明安黄土区土石混合土壤水分有效性研究Water availability in stony soil on the loess plateau土壤学201023.张超刘国彬黄土丘陵区撂荒演替中根际微生物特性演变特征生态学2010薛萐Evolution of rhizosphere microbial properties during vegetation succession on abandoned slope cropland inhilly Loess Plateau24.杨晓梅程积民子午岭天然柴松林碳储量与碳密度研究Natural Pinus shenkaneusis Forest Carbon Storage andDensity in Ziwuling Area of Loess Plateau生态学201025.韩娟娟程积民子午岭辽东栎林碳储量与土壤理化性质研究Analysis of soil physical&chemical properties &carbonstorage about liaotungensi coummnity in ziwuling草业科学201026.孟蕾程积民子午岭人工油松林碳储量与碳密度研究Carbon storage and density of artificial Pinustabulaeformis forest in Ziwuling area草业科学201027.胡秀娟程积民子午岭辽东栎、油松、柴松群落生长特征研究The growing characteristics of quercus liaotungensis、pinus tabulaeformis and pinus tabulaeformis f.shekannesisforests In ziwu region生态学201028.范文娟张继敏程积民子午岭森林群落草本植物的结构特征研究Investigation of structural charateristics of herbages underforest plantations in zi wu-ling植物学201029.夏晓娟马永清不同年份早酥梨叶片浸提液对几种套种作物的影响Allelopathic Effect of Extracts from Different Age’sLeaves of Zaosu Pear on some Intercropping Crops植物化感201030.齐治军许明祥黄土丘陵区小流域水土流失的尺度效应Effect of different cultivating models on the assimilatetranslocation in dryland wheats生态学201031.方磊刘文兆黄土高塬沟壑区砚瓦川流域径流对土地利用变化的响应研究地资源与空间信息技术201032.沈红刘文兆 GCMs在黄土高原的适用性评估土地资源与空间信息技术201033.武阿锋刘文兆长武塬区不同土地利用方式对土壤水分剖面分布的影响土壤学201034.于金凤刘文兆黄土塬区苹果树蒸腾及果园蒸散特征研究生态学201035.张盼刘文兆长武塬区地下水位变化特征研究土地资源与空间信息技术20102009年序号姓名导师硕士论文题目学科、专业毕业时间（年）36.谭贞学王占礼黄土坡面细沟侵蚀动力学过程组合小区模拟试验研究Multi-plot-based experimental modeling of dynamicprocesses of rill erosion on loess hillslope水土保持与荒漠化防治200937.马春艳王占礼黄河班多水电站工程区主要地类坡面侵蚀动力学过程试验研究Study of main slope erosion dynamic processes on project水土保持与荒漠化防治2009area of Banduo hydropower station of Yellow River38.陈绍宇王文龙高塬沟壑区溯源侵蚀发生发育规律研究—以董志塬为例Study of the development law of head-cut erosion onLoess Plateau-taking Dongzhiyuan as an example土壤学200939.冉茂勇赵允格黄土丘陵区生物结皮土壤抗冲性试验研究Experimental study on nti-scourability of soil withbiological soil crusts in hilly loess plateau region水土保持与荒漠化防治200940.陈彦芹赵允格黄土丘陵区藓结皮人工培养方法试验研究Experimental research on artificial culture of mosses crustsin hilly loess plateau region水土保持与荒漠化防治200941.刘立生张岁岐不同倍性冬小麦对水分和密度的响应Response of different ploidy winter wheat to moisture anddensity conditions生态学200942.赵紫平邓西平灌浆期水分胁迫对不同倍性小麦光合和糖代谢的影响Effect of water deficit on photosynthetic capacity andsugar metabolism of different ploidy wheat during grainfilling stage生态学200943.赵坤李世清扰动土与原状土间歇淋洗长期通气培养法反映黄土高原土壤供氮能力比较研究Comparative study of disturbing and undisturbing soillong-term alternate leaching aerobic incubation forestimating soil N supplying capacity on the Loess Plateau生态学200944.陶武辉李世清施肥对黄土高原水蚀风蚀交错区植物产量及土壤矿质氮、水溶性有机碳/氮的影响The effect of fertilizer on the plant yield, mineral nitrgen,DOC and DON in wind-water erosion crisscross region onthe loess plateau植物营养学200945.朱琳李世清栽培模式对黄土高原旱地春玉米养分累积规律及利用效率的影响The effects of different cultivation practices on the nutrientaccumulation and utilization efficiency of spring maize onthe Loess Plateau植物营养学200946.李 静 李世清 大气氨营养对小麦和玉米根冠特征及氮效率的影响Effects of atmospheric NH3 on root canopy characteristicsand nitrogen use efficiency of wheat and maize生态学200947.张 扬 李世清沈玉芳干旱胁迫及施肥对作物根系提水作用的影响Effects of drought stress and fertilizer application onhydraulic lift in crop root system生态学 200948.刘志强 杨明义 黄土高原137Cs背景值空间分布特征与影响因素研究The Spatial Distribution of 137Cs Reference Inventory andIts Influence Factors on the Loess Plateau土壤学 200949.王 彬 郑粉莉 东北典型薄层黑土区土壤可蚀性关键因子分析与土壤可蚀性计算Key factors and calculation of soil Erodibility in thetypical eroded Black soil area of northeast china水土保持与荒漠化防治200950.丁晓斌 郑粉莉 基于GIS的坡面水文—侵蚀预报模型初步研究Hillslope Hydrology-Erosion Prediction Model Based onGIS地图学与地理信息系统200951.崔艳平 郑粉莉 近地表土壤水文条件对坡面土壤侵蚀和氮、磷养分流失的影响研究Effect of near-surface soil hydrological conditions on soilerosion and nutrient losses At hillslopes水土保持与荒漠化防治200952.张会茹 郑粉莉 红壤坡面与黄土坡面土壤侵蚀过程对比研究Comparitive study upon soil erosion processes on red soilhillslope and loess hillslope水土保持与荒漠化防治200953.白一茹 邵明安 水蚀风蚀交错带坡面土壤水分特性研究Study on soil water properties on slope in water-winderosion crisscross region on the loess plateau环境科学 20092008年序号姓名导师硕士论文题目学科、专业毕业时间（年）54.龚家国王文龙黄土坡面浅沟侵蚀影响因素及水动力过程模拟试验研究Experimental study on Influencing Factors and dynamicprocess of ephemeral gully erosion on Losses slope土壤学 200855.徐龙江杨明义黄土高原小流域洪水泥沙来源的复合指纹分析法研究Study on the Composite Fingerprinting Flood SuspendedSediment Sources in the Catchment on the Loess Plateau土壤学 200856.王英黄明斌径流曲线法（SCS-CN）的改进及其在黄土高原的应用Optimizing and Improving SCS-CN Method in LoessPlateau土壤学 200857.王凯博上官周平子午岭植被演替过程中物种多样性研究Studies on the species diversity In vegetation succession Inziwuling area生理生态 200858.邓娟上官周平子午岭人工油松林自然发育过程及其特征研究Study of the natural development and the characteristics ofartificial pinus tabuleaformis forest in ziwuling region生理生态 200859.邵瑞鑫上官周平外源NO 对水分亏缺下小麦叶片光合能力的调控效应The effectsof exogenousnitricoxide on Regulatingphotosynthetic capacity of Wheatleaves under waterdeficit生理生态 200860.陈美玲上官周平子午岭林区植被群落植物优势种能量和养分特征研究Energy and nutrient characteristics of the dominant plantspecies in ziwuling forest of the loess plateau生理生态 200861.段军彪上官周平黄土高原小流域侵蚀预测与景观虚拟研究Research on Soil Erosion Prediction and Virtual RealityLandscape in Small Watershed of Loess Plateau计算机应用技术200862.李静上官周平黄土坡面水蚀模拟的关键技术研究Research of key technology of water erosion simulation inloess slope计算机应用技术200863.连振龙刘普灵黄土丘陵区典型流域植被恢复减沙效益研究Study on Effect of Vegetation Restoration on SedimentReduction in the Loess Hilly Region土壤学 200864.周小平张岁歧玉米根系生长、功能的基因型差异及其对水分利用效率的影响Root growth and function of different genotype maize andits effection on water use efficiency生态学 200865.黄传琴邵明安干湿交替过程中土壤胀缩特征的试验研究Experimental Study on Soil Shrinking and SwellingCharacteristics during the Alternative Drying and WettingProcesses土壤学 200866.王幼奇邵明安樊军水蚀风蚀交错带典型植被蒸散特征研究Study on evapotranspiration of vegetation in water-winderosion crisscross region on the loess plateau土壤学 200867.赵爱辉黄明斌黄土水力参数的测定与间接推求方法研究Hydraulic Parameters Measurements and Estimations forLoess Soils土壤学 200868.刘雨安韶山郑粉莉黄土高原丘陵沟壑区燕沟流域植被恢复对土壤质量的影响研究Effects of vegetation restoration on soil quality in yangoucatchment in hilly-gully region of the loess plateau水土保持与荒漠化防治200869.汪晓勇郑粉莉黄土坡面土壤侵蚀—搬运过程试验研究An experimental study on soil detachment and transportprocesses at loessial hillslope水土保持与荒漠化防治200870.张鹏郑粉莉沟蚀发育过程动态监测研究Monitoring of gully erosion development: Process anddynamics土地资源与空间信息技术200871.张长保李世清王全九樊军降雨条件下黄土坡面土壤养分迁移特征试验研究Loess slope nutrient migration experimental Study onrainfall condition植物营养学 200872.宋翔李世清王全九樊军黄土旱塬冬小麦产量与水氮及其耦合关系模型的研究Study on the relation between winter wheat yield andwater-nitrogen and its interaction modle on the LoessDryland植物营养学 200873.冯宏昭李世清降雨对玉米冠层磷素淋洗的研究Effect of rainfall on phosphorus leaching in maize conopy生态学 200874.党蕊娟李世清施氮对冬小麦/夏玉米光合调控的研究Study on photosynthesis regulation of winter wheat/summer maize by nitrogen applied植物营养学 200875.华瑞李世清介质供磷水平对冬小麦/玉米苗期生长过程的调控作用Regulation of phosphorus supplying rates on the WinterWheat-Maize seedling growthing process植物营养学 200876.闫登明李世清氮素形态和铁营养对几种作物同化过程及体内铁分布的影响Effec of nitrogen forms and iron nutrition on assimilation植物营养学 2008process and iron distribution of different crops77.穆晓慧李世清黄土高原农田土壤Cd和P形态分级及生物有效性研究Study on cd and p fractionation and bioavailability infarmland soil of the loess plateau农业环境保护与食品安全20082007年序号姓名导师硕士论文题目学科、专业毕业时间（年）78.刘小芳张岁岐单根和细胞水平玉米根系吸水的杂种优势The Heterosis of Water Uptake by Roots of Maize atSingle Root and Cell Level生态学 200779.田风霞王占礼郑世清黄土山坡植物路防蚀效应模拟试验研究Experimental Modeling of Anti-erosion Benefits of PlantRoad on Loess Hillslope土壤学 200780.谭红朝李秧秧黄土丘陵区几种主要树木径向生长、液流及其与环境条件的关系The Radial Growth, Sap Flow of Several Trees and theirRelation with Environmental Factors in the Loess Hilly Area生态学 200781.周雪英邓西平不同倍性小麦对旱后复水的生理生态响应Physiological effects of post-drought And rewatering onwheat with different pliody生态学 200782.李建梅邓西平转Cu/Zn-SOD、APX基因甘薯对水分胁迫及复水的生理生化响应Physiological and biochemical responses of transgenicsweet potato expressing both cu/zn-sod and apx genes todrought and rewatering conditions生态学 200783.韦兰英上官周平黄土高原不同演替阶段草地植被细根分布及其生态特征研究Study on the vertical distribution and ecologicalcharacteristic of the fine root in different abandonded yeargrassland in loess plateau生态学 200784.刘勇上官周平子午岭典型森林群落生物量与土壤水分、养分的关系The relationship between community biomass and soilmoisture 、soil nutrient i n ziwuling typical forests生态学 200785.付晓莉邵明安土壤水分特征曲线测定过程中的压实效应研究Study on compaction effects during soil watercharacteristic Curve measurement环境科学 200786.丛 伟张兴昌重金属Se在土壤中的运移规律研究Solute transport regularity of se in soil土壤学 200787.张晋爱张兴昌黄土高原不同植被覆盖下土壤性质的时空变异特征Temporal and spatial variability of soil quality underdifferent vegetation covering on the loess plateau土壤学 200788.南维鸽李世清田间杂草对冬小麦产量及氮素利用效率的影响The Effects of Weeds on the Winter Wheat Yield and theNitrogen Use Efficiency植物营养学 200789.金发会李世清黄土高原土壤供氮能力测定方法的比较研究Comparison of the methods of assessing soil n-supplyingcapacity on loess plateau植物营养学 200790.侯红乾李世清冬小麦-杂草氮素营养竞争研究Study on nitrogen competition between winter-wheat andweed植物营养学 200791.王锦峰李世清不同栽培模式和施氮水平对冬小麦籽粒产量及蛋白质形成的影响Effects of different cultivation mode and nitrogenprovision levels on construction of output and protien ofwinter wheat grains植物营养学 200792.张国桢李世清石灰性土壤硝化作用模型的研究S studing on the nitrification kinetic models In thecalcareous soil种植 200793.李小霞李世清栽培模式、施氮量和播种密度对冬小麦冠层及产量构成特征的影响The effect of cultivate mode, nitrogen fertilizer rate andplanting density on the winter wheat conpy and yieldcharacters作物生理生态200794.王建勋郑粉莉WEPP模型（坡面版）在黄土高原丘陵沟壑区的适用性评价Assessment on WEPP Model Applicability（Hillslopeversion）to the Hilly-gully Region of the Loess Plateau水土保持与荒漠化防治200795.王志刚李靖郑粉莉不同近地表水文条件下紫色土坡耕地土壤侵蚀过程研究Study on Purple Soil Erosion Process at Sloping CultivatedField under Different Surface Hydrological Condition水土保持与荒漠化防治20072006年序号姓名导师硕士论文题目学科、专业毕业时间（年）96.秦娟上官周平子午岭林区山杨－辽东栎混交林生理生态效应研究Eco-physiological Effect of Populus davidiana-Quercusliaotungensis Mixed Forests in Ziwuling Forest Area生态学 200697.吴安慧张岁岐玉米根系AQP表达的基因型差异及其与抗旱性的关系The expression differences of aquaporins genes in maizeroots among genotypes and its relation with droughtresistance生态学 200698.李筠邓西平水分胁迫对转Cu/Zn SOD 和APX基因甘薯抗氧化和叶绿素荧光的影响Effect of water stress on antioxidation and chlorophy Ⅱfluorescence of Cu/Zn SOD and APX gene transferredsweet potato生态学 200699.胡伟邵明安王全九黄土坡面土壤水分时空变异性研究Temporal-Spatial Variability of Soil Moisture on aSlope-land on the Loess Plateau生态学 2006100.牛振华王占礼坡面土壤侵蚀物理模型及其率定与验证Physically-based Model of Soil Erosion on Hillslope andIts Calibration and Validation土壤学 2006101.韩凤朋张兴昌黄土高原小流域不同尺度土壤养分的空间变异Spatial variability of soil nutrient on slope and watershedscale on the Loess Plateau土壤学 2006102.范亚宁李世清云雾山草地小尺度植物多样性及土壤-植物养分空间变异性研究Study on plant diversity and soil-plant spatial variability insmall scale in yunwu mountain grassland生态学 2006103.刘毅李世清黄土高原不同生境条件下土壤结构体分形及碳、氮分布Fractal dimensions of soil aggregates and istribution ofcarbon and nitrogen from different environments in theLoess Plateau植物营养学 2006104.吉春容李世清品种、种子大小和施肥对冬小麦生物学性状、光合-荧光特征和氮磷养分效率的影响Effect of variety, seed size and fertilization oncharacteristics of biological and photo synthesis-fluorescence, nutrition efficiency of n and p of winter wheat生态学 2006105.李紫燕李世清黄土高原典型土壤有机氮矿化及铵态氮对土壤氮素激发效应的研究Study on the primin effect caused by ammonium andMineralizaton of organic nitrogen in the typical soils onLoess Plateau植物营养学 2006106.刘殿红黄占斌保水剂对马铃薯生长效应及其机理研究A study on effect of aquasorb on growth of potato and itsacting mechanism生态学 2006107.李建玲黄占斌多功能保水剂对马铃薯产量和水分利用效率(WUE)影响研究Effects of multi-function aquasorb on yield and water useefficiency (WUE) of potatoes生态学 2006108.迟永刚黄占斌李茂松小麦进化过程中的光合生理特性研究Study on the photosynthetic characteristics of wheat inprocess of evolution生态学 2006109.曾辰邵明安水蚀风蚀交错带不同植被覆盖条件坡面土壤水分循环的实验研究Study on the soil water cycle on slope with differentconditions of vegetation covering in water-wind erosioncrisscross region土壤学 2006110.刘春利邵明安水蚀风蚀交错带坡地土壤物理特性时空变异性研究Study on soil physical properties temporal-spatial variabilityof a slope in the wind-water erosion crisscross region生态学 2006111.史磊邓西平水分胁迫下不同基因型小麦光合特性的比较研究Photosynthetic characteristics of different wheat genotypesunder water stress生态学 2006112.申震洲谢永生刘普灵REE示踪研究坡面侵蚀过程及不同下垫面撂荒地的减沙效益Study on the processes of soil erosion using ree tracers onsloping land and the effect on reducing sediment ofdifferent underlying surfaces土壤学 2006113.刘力郑粉莉紫色土和黄土坡耕地土壤侵蚀过程对比研究Comparison study on purple soil and loess soil erosionprocesses at sloping cultivated field水土保持与荒漠化防治2006114.吕春花郑粉莉子午岭地区植被恢复对土壤质量的影响研究Effects of Vegetation Restoration on Soil Quality in theZiwuling Area水土保持与荒漠化防治2006115.张锋郑粉莉子午岭地区植被破坏加速侵蚀对土壤质量退化过程的影响Effects of accelerated erosion caused by deforesation onsoil quality degradation process in the ziwuling area水土保持与荒漠化防治2006116.王振宇李凤民水分胁迫和断根对冬小麦根源信号、竞争能力及与产量形成的关系Root-sourced signals, competitive ablity and It’srelationship with yield of winter wheat Affected by rootexcision in a semiarid植物生理生态20062005年序号姓名导师硕士论文题目学科、专业毕业时间（年）117.张煜邓西平水分胁迫对不同进化小麦抗氧化与叶绿素荧光的影响Effect of water stress on antioxidation and chlorophyllfluorescence of different evolutionary types of wheat生态学 2005118.王周锋张岁岐玉米根系水导差异的生理生态原因分析Analysis on physiological and ecological reason for lprdifference of root system of maize生态学 2005119.黄新会王占礼黄土区坡面水文模型研究Hydrology Prediction Model of Loess Hillslope水土保持与荒漠化防治2005120.赵琳李世清氮肥和栽培模式对半湿润农田生态系统冬小麦个体-群体调控的研究The study of nitrogenous fertilizer and planting modesonthe relationship between individual and colony of winterwheat in the sub-humid area ecology system植物营养学 2005121.沈新磊李世清冬小麦源库大小改变对产量构成及产量的影响Effects of Winter Wheat Source-Sink Change on theYields and Yield Structures植物营养学 2005122.王瑞军李世清农牧交错带地膜春玉米生态特征及其氮肥效应的研究Study on ecological characteristics and nitrogen Effect ofplastic film-mulching spring corn in the Crisscross regionof agriculture-pasture植物营养学 2005123.张安邦上官周平李秧秧黄土高原半干旱区小流域生态水文效应及过程模拟Ecohydrological Effect and Hydrological Processes生态学 2005Simulation in the small catchment of the Loess Pleatu’ semiarid area124.薛晓辉张兴昌黄土高原植被恢复对土壤碳、氮养分的影响Effect of re-vegetation on soil carbon and nitrogen on theLoess Plateau土壤学 2005125.丁晋利郑粉莉7Be示踪坡面土壤侵蚀过程及机理研究Application of 7Be to Quantifying Soil Erosion Processand Mechanism at Hillslope土壤学 2005126.武敏郑粉莉坡面汇流汇沙与浅沟侵蚀过程研究Effects of Up-slope Runoff and Sediment on EphemeralGully Erosion Process at Loess Hillslopes水土保持与荒漠化防治20052004年序号姓名导师硕士论文题目学科、专业毕业时间（年）127.潘成忠上官周平黄土区草地坡面侵蚀产沙过程的调控Grass vegetation influence on plot erosion sedimentproducing processes on loess area生态学 2004128.张亚丽张兴昌径流与土壤矿质氮素作用深度的确定Confirmation of the effective depth of interaction ofrunoff with soil mineral nitrogen土壤学 2004129.贾媛媛郑粉莉王占宏黄土丘陵沟壑区小流域分布式水蚀预报模型初步研究Distributed water erosion prediction model at smallwatershed scale in the loessial hilly-gully region水土保持与荒漠化防治2004130.王红闪黄明斌黄土沟壑区不同植被类型水文生态演变研究Study on hydroecological environmental changes underdifferent types of vegetation in the gully region of theLoess Plateau土壤学 2004131.辛小桂黄占斌保水剂及其功能复合材料对玉米生长和抗旱性的影响Effect of aquasorb and its compound materials withmulti-function on growth and drought resistance of maize生态学 2004132.袁永慧邓西平不同基因型小麦变水条件下的补偿效应研究Compensatory effect of different wheat genotypes underwater deficient and rewatering conditions生态学 2004133.薛亚洲刘普灵利用REE示踪技术研究黄土坡面土壤侵蚀演变过程Using rare-earth elements tracers technology to studyspatial and temporal processes of Soil Erosion on slopingland of the Loess Plateau水土保持与土壤侵蚀2004134.杨晓青梁宗锁张岁岐不同类型冬小麦品种根系特性及其与WUE的关系研究Study on relations between roots characteristics and WUEof different type winter wheat varieties植物水分生理生态2004135.朱元骏黄占斌保水剂模拟非均衡根土水环境下玉米生长和WUE研究Growth and WUE of maize in heterogeneous roots-soilwater environment simulated by aquasorb生态学 2004136.贾松伟贺秀斌黄土丘陵区土壤侵蚀对土壤有机碳迁移的影响水土保持与2004陈云明The effect of soil erosion on soil organic carbon migrationin Loess hilly region of northwestern China荒漠化防治2003年序号姓名导师硕士论文题目学科、专业毕业时间（年）137.张文菊吴金水三江平原典型湿地生态系统有机碳积累及影响机制研究Study on the accumulation of organic carbon and it’saffecting mechanism of typical wetland ecosystem insanjiang plain, north-east China土壤学 2003138.周印东吴金水子午岭植被演替过程中土壤有机碳积累与变化Study on the accumulation of soil organic carbon in thevegetation successions in Ziwuling region土壤学 2003139.方峰黄占斌大垄沟改良措施对玉米生长和WUE影响的研究Study on the effect of broad ridge improved measures tomaize growth and water use efficiency生态学 2003140.俞满源黄占斌保水剂与氮肥对马铃薯生长和WUE效应及其机制研究The response of growth and water use efficiency of potatoto aquasorb and nitrogen and it’s mechanism生态学 2003141.郭彦彪李占斌流域地貌形态与降雨侵蚀产沙关系研究Study on relationship between watershed topography andsediment yield by rainfall erosion in loess area水土保持与荒漠化防治2003142.郑良勇李占斌黄土地区陡坡水蚀动力过程试验研究Experimental study on dynamic process of soil erosion onloess slope水土保持与荒漠化防治2003143.毛明策史俊通上官周平黄土高原节水农业专家系统的研制The development of the water saving agricultural expertsystem of Loess Plateau作物栽培学与耕作学2003144.李立青刘普灵7Be和137Cs复合示踪坡耕地土壤侵蚀产沙的空间分布特征Use of 7Be and 137Cs measurements to study the patternof soil erosion on cultivated slope land土壤学 2003145.宋炜刘普灵利用REE示踪法研究黄土坡面土壤侵蚀过程Using REE tracers to measure sheet erosion changing torill erosion on loess slope水土保持与荒漠化防治2003146.白登忠邓西平水分亏缺下番茄水分传输途径和根冠大小对蒸腾和WUE的调控Tomato transpiration and WUE regulated by water transportpath and size of shoot and root under water deficit生态学 2003147.黄明丽邓西平不同基因型小麦水分、养分利用效率的比较研究Comparison of water and nutrient use efficiencies indifferent wheat genotypes生态学 2003148.王生毅邓西平干旱胁迫对番茄根系水导的影响及液泡膜水通道蛋白表达量检测研究Research on water transportation of drought stressed tomatoroot systems and tonoplast aquaporins expression quantity生物化学与分子生物学2003149.王辉雷廷武径流含沙量与流量机电一体化测控系统研究及应用An automatically controlled system for measurement ofsediment and discharge rate of runoff and its applications水土保持与荒漠化防治2003150.冒建华雷廷武草地集中水流土壤侵蚀室内模拟试验及聚丙烯酰胺（PAM）对草地出苗影响试验研究Laboratory simulation experiments on soil erosion fromgrass-covered surface under concentrated flow and theeffects of pam on the germination of Alfalfa水土保持与荒漠化防治2003151.张丽张兴昌水分-氮素-光照对玉米生长的互作效应Interactions of nitrogen, water with light on the growth ofmaize土壤学 2003152.何福红黄明斌党廷辉黄土高原沟壑区小流域水文性质的空间变异性Spatial variability of hydrological properties in acatchment of the gully region, the Loess Plateau土壤学 2003153.慕自新梁宗锁张岁岐玉米根系特征与其水分关系研究Studies on maize root traits and whole plant water relations植物学 20032002年序号姓名导师硕士论文题目学科、专业毕业时间（年）154.景为邵明安推求土壤非饱和运动参数的方法Estimating Methods for Soil Hydraulic Properties土壤学 2002155.彭浩邵明安张兴昌黄土区土壤钾素径流流失规律研究Research on Soil Potassium Loss by Erosion in Loessial Area土壤学 2002156.卢金伟李占斌土壤团聚体水稳定性及其与土壤可蚀性之间关系研究Study on relation between water stability of soil aggregateand soil erodibility水土保持与荒漠化防治2002157.刘纪根雷廷武坡耕地施加PAM降雨入渗产流及侵蚀产沙规律试验研究Study on the Laws of Rainfall Infiltration Runoff andErosion Sediment on Slopeland Treated With PAM土壤学 20022001年序号姓名导师硕士论文题目学科、专业毕业时间（年）158.郑纪勇邵明安土壤中溶质运移的边界层方法Boundary Layer 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高含硫气井采气树冲蚀规律研究
高含硫气井采气树冲蚀规律研究发布时间：2022-06-23T07:35:04.470Z 来源：《中国科技信息》2022年第33卷2月第4期作者：唐弢[导读] 普光气田为高含硫气藏，单井产量高唐弢中国石化中原油田分公司石油工程技术研究院，河南濮阳 457001摘要：普光气田为高含硫气藏，单井产量高，在生产过程中，井口装置出现了不同程度的腐蚀与硫沉积，本文利用计算流体力学研究了不同产量、不同颗粒直径、不同颗粒质量流量、不同井口压力、不同气体二氧化碳浓度条件下井口设备冲蚀规律，研究发现随着高含硫气井产量、硫颗粒直径、颗粒质量流量、井口压力、二氧化碳浓度增大井口冲蚀越严重，井口更易发生腐蚀失效。
其中，气体产量与颗粒质量流量对井口冲蚀规律影响较大，其它因素影响较小，因此，在高含硫气井实际生产中应合理控制生产参数，减少高含硫气井井口硫单质析出，以保证高含硫气井安全生产。
关键词：普光气田；冲蚀；采气树；高含硫气井随着石油勘探水平的提高，国内外高含硫油气藏数量激增，高含硫气田井井口腐蚀严重影响气井安全生产，然而，高含硫气井生产过程中更多关注酸性气体对井口的化学腐蚀，但硫颗粒析出对井口的冲蚀作用严重危害井口设备安全性，在高产气井中冲蚀腐蚀是影响井口安全的重要因素之一。
针对油气井冲蚀腐蚀国内外学者开展了大量研究，有研究表明，当气体流速超过一定范围，随钻流速的增大，冲蚀腐蚀加剧[1-3]；吴欢欢等人[4]针对含砂石油对三通管冲蚀开展了研究，摩损速率对速度或颗粒质量分数的增大而增大，但最大磨损率的位置与速度和颗粒质量分数无关；张恩博等人[5]运用CFD数值模拟方法对高压高产气井应急试采过程中采气树冲蚀进行了研究，通过研究发现采气树冲蚀速率随着气井产量与日出砂量增大而增大；Liu等人[6]研究了气体钻井对井口四通冲蚀规律，发现两翼支管出口处冲蚀最严重。
邹康等人[7-10]对气体钻井口多功能四通开展了大量研究，研究表明冲蚀速率与流体速度、岩屑质量流量呈线性递增，与岩屑颗粒大小成反比，出口压力影响较小。
冲蚀研究现状
冲蚀磨损是指液体或固体以松散的小颗粒按一定的速度或角度对材料表面进行冲击所造成的一种材料损耗现象或过程。
它广泛存在于机械、冶金、能源、建材、航空、航天等许多工业部门，已成为材料破坏或设备失效的重要原因之一[63~65]。
根据流动介质和所携带相的特点，可以将冲蚀磨损分为六种不同的类型[66]：(1)喷砂型冲蚀，即气体介质携带固体颗粒对材料的冲蚀，其工程实例为烟气轮机、锅炉管道等出现的破坏；(2)水滴冲蚀(又称雨蚀)，即气体介质携带液滴对材料的冲蚀，其工程实例为高速飞行器、汽轮机叶片出现的破坏等；(3)泥浆(又称料浆)冲蚀，即液体介质携带固体颗粒对材料的冲蚀，其工程实例如水轮机叶片、泥浆泵叶轮出现的破坏；(4)气蚀(又称空蚀)，即液体介质携带气泡对材料的冲蚀，工程实例如船用螺旋桨、高压阀门密封面出现的破坏；还有两种类型为三相流冲蚀，即(5)气体介质同时携带液滴和固体颗粒对材料的冲蚀；(6)液体介质同时携带气泡和固体颗粒对材料的冲蚀。
本文研究的冲蚀磨损主要是固液两相，可以归到上述的第3 类。
1958 年，从Finnie. I 第一个冲蚀理论－微切削理论提出以来，许多研究者提出了一些关于冲蚀的模型[67~74]，但到目前为止，人们仍未能全面揭示材料冲蚀的内在机理[75]。
Finnie. I 解释了塑性材料在多角形磨粒、低冲击角下的磨损规律，但对高冲击角或脆性材料的冲蚀偏差较大；1963 年，Bitter[76]提出变形磨损理论，该理论在单颗粒冲蚀磨损试验机上得到验证，合理地解释了塑性材料的冲蚀现象，但缺乏物理模型的支持。
Levy[77]在大量实验的基础上提出来的锻压挤压理论：使用分步冲蚀试验法和单颗粒寻迹法研究冲蚀磨损的动态过程。
该理论较好地解释了显微切削模型难以解释的现象。
1979 年，Evans 等人提出的弹塑性压痕破裂理论[78]。
大量试验证明，该理论很好地反映了靶材和磨粒对冲蚀磨损的影响，试验值和理论值也较吻合，但不能解释脆性粒子以及高温下刚性粒子对脆性材料的冲蚀行为。
原子氧作用下聚酰亚胺薄膜剥蚀形貌仿真方法
第 40 卷第 4 期航 天 器 环 境 工 程Vol. 40, No. 4 2023 年 8 月SPACECRAFT ENVIRONMENT ENGINEERING367 https:// E-mail: ***************Tel: (010)68116407, 68116408, 68116544原子氧作用下聚酰亚胺薄膜剥蚀形貌仿真方法焦子龙1,2，乔世英1,2，姜海富1,2，姜利祥1,2，刘宇明1,2，徐焱林2，李 涛3（1. 可靠性与环境工程技术重点实验室； 2. 北京卫星环境工程研究所：北京 100094；3. 中国航天科技集团有限公司，北京 100048）摘要：为研究低地球轨道（LEO）原子氧(AO)作用下航天器用聚酰亚胺（PI）薄膜材料剥蚀形貌变化规律，提出一种基于局部网格边界相交判断的剥蚀形貌仿真方法，并采用周期性边界处理法获得表面形貌。
其计算所得材料掏蚀深度与文献中的试验结果相差小于4%，证明该方法对AO与PI材料的相互作用的仿真与试验结果相近。
采用剥蚀深度算术平均偏差和标准差作为形貌的描述参数，发现这2个参数均随着AO累积通量以0.253次幂律增大。
标准差和算术平均偏差的比值随AO累积通量的增大基本保持不变，说明表面形貌特征在AO作用下基本不变，只是表面峰值和谷值增大。
此外，计算结果表明，不同轨道速度条件下PI表面剥蚀形貌差异不大。
以上研究结果有助于进一步理解AO作用下PI材料表面剥蚀形貌形成机理。
关键词：原子氧；剥蚀；表面形貌；聚酰亚胺；仿真分析中图分类号：V250.4; TB115文献标志码：A文章编号：1673-1379(2023)04-0367-07 DOI: 10.12126/see.2023014A method for simulating surface erosion morphology of polyimidefilm under atomic oxygen attackJIAO Zilong1,2, QIAO Shiying1,2, JIANG Haifu1,2, JIANG Lixiang1,2, LIU Yuming1,2, XU Yanlin2, LI Tao3(1. Key Laboratory of Reliability and Environmental Engineering Technology;2. Beijing Institute of Spacecraft Environment Engineering: Beijing 100094, China;3. China Aerospace Science and Technology Corporation, Beijing 100048, China)Abstract: In order to study the erosion morphology of polyimide (PI) film materials under atomic oxygen (AO) attack in low Earth orbit (LEO), a method based on the intersection simulation of local grid boundaries was proposed. The periodic boundary method was applied to obtain the surface morphology. The difference between the calculation results of the erosion morphology and those of the experimental results in the literature was less than 4%, which proved that the interactions between AO and PI materials simulated by the proposed method was close to the experimental results. Using the arithmetic mean deviation and standard deviation of erosion depth as the morphology description, it was found that these two parameters all increased by power 0.253 with the increase of AO fluence. The ratio of standard deviation to arithmetic mean deviation remained basically unchanged with the increase of AO fluence, indicating that the surface morphology remained basically unchanged under the AO attack, when only the height of peaks and the depth of valleys increased. In addition, there was little difference in the surface erosion morphology of PI under different orbital velocities. The above results help to further understand the formation mechanism of PI surface erosion morphology under AO attack.Keywords: atomic oxygen; erosion; surface morphology; polyimide; simulation analysis收稿日期：2023-02-18；修回日期：2023-07-30引用格式：焦子龙, 乔世英, 姜海富, 等. 原子氧作用下聚酰亚胺薄膜剥蚀形貌仿真方法[J]. 航天器环境工程, 2023, 40(4): 367-373JIAO Z L, QIAO S Y, JIANG H F, et al. A method for simulating surface erosion morphology of polyimide film under atomic oxygen attack[J]. Spacecraft Environment Engineering, 2023, 40(4): 367-3730 引言聚酰亚胺（PI）是性能优异的航天器用聚合物材料 ，广泛应用于热控材料[1-2]、柔性太阳电池基板和电路系统绝缘材料[3]等，作为帆面材料在太阳帆[4-5]和离轨帆[6]等新型空间应用方面也逐步得到重视。
关于含有木糖醇产品对口腔的利与弊
关于含有木糖醇产品对口腔的利与弊张泓灏2009级口腔医学113200900400010现在，不同的糖替代品被介绍和广泛应用于各种甜食和饮料中来避免牙齿因糖和其他碳水化合物而发生龋坏。
其中一组糖替代品就是多元醇。
多元醇已经被明确地使用于糖尿病人的食物中因为多元醇不容易被肠和血流吸收，有阻止餐前血糖水平的提高，降低了热量摄入的作用。
但是，木糖醇产品对口腔健康的作用是单方面的有利，还是双方面的有利有弊呢？我针对木糖醇产品对牙齿腐蚀的影响作用进行文献查找，尝试得出结果。
一篇在2011年发表在Journal of Oral Science的文献提出：加入木糖醇的含氟牙膏可以明显地对抗牙齿腐蚀，甚至对增加了摩擦作用的牙齿腐蚀也要明显的对抗效果。
实验的目的是析含有木糖醇的含氟牙膏在给予和不给予摩擦的情况下的对釉质腐蚀提供的保护作用。
实验使用离体的牛釉质样本，经过腐蚀或者腐蚀加摩擦7天的时间，然后给予含有各种成分的牙膏的处理。
每个组的一半样本增加了一个电动牙刷的摩擦作用（摩擦力为1.5N），在每次的腐蚀考验之间，样本会被人工唾液再矿化。
釉质损失通过轮廓测定法测定。
数据通过双因素方差分析和邦弗朗尼事后检验法（P<0.05）进行双因素分析。
结果表明加入的10%木糖醇在离体实验中增加了含氟牙膏的对抗釉质摩擦腐蚀的效果。
可见，木糖醇有辅助氟防龋的作用。
另外的一篇在2011年发表在British Dental Journal的综述却提出了一个备受我们忽视的情况。
木糖醇产品的确对牙齿龋坏有明显的阻止作用，但是木糖醇产品中含有其他的成分例如酸性调味剂，防腐剂，这些成分会对牙齿产生腐蚀作用。
这些还需要更深入的研究。
综上所述，我们应该辩证地看待木糖醇产品的对口腔健康的作用，既要看到木糖醇的防龋性，也要看到木糖醇产品含有的其他成分对牙齿的副作用。
参考文献：[1] Rochel ID, Souza JG, Silva TC. Effect of experimental xylitol and fluoride-containing dentifrices on enamel erosion with or without abrasion in vitro. J Oral Sci.2011 Jun;53(2):163-8.[2] Nadimi H, Wesamaa H, Janket SJ. Are sugar-free confections really beneficial for dental health? Br Dent J.2011 Oct 7;211(7):E15.。
美国国家自然科学基金
工信部和应急管理部印发《“工业互联网+安全生产”行动计划(2021—2023年)》
・58・中国安全生产科学技术第16卷tor[J].Science Technology and Engineering#2018,18(15)：94-98.[8]赵饪，龚盼，刘志刚，等•新型射流振荡器工作原理与试验研究+J]•流体机械,2018,46(9)：13-17,83.ZHAO Yu,GONG Pan,LIU Zhigang,et al.Working principle and experimental research of a new type fluidic oscillatos+J].Fluid Ma-choneey,2018,46(9)：13-17,83.[9]胡成，邓福成，杨永刚，等•基于正交试验的割缝筛管冲蚀磨损分析+J]•石油机械，2020,48(1)：149-54.HU Cheng,DENGFucheng,YANG Yonggang,eiaa.Anaaysoson eeo-sion weas of slotted screen tubs based on orthogonal test+J].China Peieoaeum Ma ch one ey,2020,48(1)：149-1549[10]向正新，李思行，钱利勤，等•压裂球座冲蚀磨损规律研究和结构优化+J]•工程设计学报,2017,24(5)：555-562.XUNG Zhengxin,LI Sixing,QIAN Liqin,et al.Research on erosionwear law and structure optimization of fracturing ball seat+J].Jous-nal of Engineering Design,2017,24(5)：555-562.[11]吴(，刘少胡，刘旭辉，等•焊肉位置对连续管冲蚀磨损规律研究+J]•中国安全生产科学技术,2017,13(2)：138-142.WU Han,LU Shaohu,LU Xuhui,et al.Study on the erosion andabrasion law of continuous pips by welding meat position+J].Jous-nal of Safety Science and Technology,2017,13(2):138-142.[12]HATTORI S,KISHIM O M.Prediction of cavitation erosion onstainless steel components in centrifugal pumps+J].Weas,2008,265(11-12)：1870-1874.[13]成芳，易先中，彭灼，等•页岩气压裂弯管中液固两相流冲蚀磨损的数值模拟+J]•中国安全生产科学技术,2019,15(11":29-35.CHENG Fang, YI Xianzhong,PENG Zhuo,et al.Numerical simulation of liquiX-soliX tuo-phase flow erosion and wear in shale gasfracturing elbow+J].Journal of Safety Science and Technology,2019,15(11)：29-35•[14]黄坤，邓平，李岳鹏，等•气固两相流90。
压裂泵泵阀冲蚀磨损的数值模拟
第51卷第8期表面技术2022年8月SURFACE TECHNOLOGY·225·压裂泵泵阀冲蚀磨损的数值模拟胡锦程1a,1b，李蓉2，李登1a,1b，胡毅1a,1b，刘铮1a,1b，王晓川1a,1b(1.武汉大学 a.动力与机械学院 b.水射流理论与新技术湖北省重点实验室，武汉 430072；2.江汉石油管理局第四机械厂，湖北 荆州 434022)摘要：目的研究压裂泵作业过程中泵阀阀隙流场的冲蚀磨损特性，探究其主要影响因素与影响规律。
方法基于固液两相流基本理论与冲蚀模型，采用计算流体力学（CFD）方法模拟泵阀阀隙流场的冲蚀磨损行为，探究支撑剂粒径、质量流量、泵阀半锥角、阀座孔入口半径、阀盘升程等参数对泵阀冲蚀特性的影响。
结果泵阀的冲蚀磨损主要表现为支撑剂对阀盘边缘处的直接冲击与对阀座锥面处的切削作用。
支撑剂粒径由0.062 5 mm增大到0.375 mm时，最大冲蚀速率增大了4.80倍，继续增大到1.5 mm时，最大冲蚀速率减小了76.12％；当其质量流量由5 g/s增大到25 g/s时，最大冲蚀速率增大了3.84倍。
当泵阀半锥角由30°增大到50°，阀盘升程由5 mm增大到15 mm时，最大冲蚀速率分别减小了95.55％与92.57％；随着阀座孔入口半径由30 mm增大到50 mm，最大冲蚀速率增大了10.47倍。
同时，阀盘升程的增大还会显著影响冲蚀磨损区域的分布。
结论压裂泵泵阀的最大冲蚀速率随支撑剂粒径的增大先增大后减小，随阀座半锥角与阀盘升程的增大而减小，随支撑剂质量流量与阀座孔入口半径的增大而增大。
其中，泵阀结构参数对泵阀冲蚀磨损的影响更为显著。
关键词：压裂泵泵阀；冲蚀磨损；数值模拟；固液两相流；流动规律；颗粒运动行为中图分类号：TH117.1文献标识码：A 文章编号：1001-3660(2022)08-0225-08DOI：10.16490/ki.issn.1001-3660.2022.08.018Numerical Simulation for Erosive Wear of the Fracturing Pump Valve HU Jin-cheng1a,1b, LI Rong2, LI Deng1a,1b, HU Yi1a,1b, LIU Zheng1a,1b, WANG Xiao-chuan1a,1b(1. a. School of Power and Mechanical Engineering, b. Hubei Key Laboratory of Waterjet Theory and NewTechnology, Wuhan University, Wuhan 430072, China; 2. SJ Petroleum Machinery Co., Jianghan PetroleumAdministration, Hubei Jingzhou 434022, China)ABSTRACT: In this paper, the erosive wear characteristics of pump valve gap flow field in the operation process of fracturing pump valve, including the main influence factors and their influence law was studied. Based on the theory of the solid-liquid two-phase flow and the erosion model, the computational fluid dynamics (CFD) method was used to simulate the erosive wear收稿日期：2021–08–15；修订日期：2021–10–13Received：2021-08-15；Revised：2021-10-13基金项目：国家自然科学基金项目（52074194）Fund：National Natural Science Foundation of China (52074194)作者简介：胡锦程（1997—），男，博士研究生，主要研究方向为多相流及流固耦合振动。
damage句子精选66句
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wear down作主语
Wear DownIntroduction“Wear down” is a phrase that implies gradually diminishing or reducing something through continuous use or friction. This concept can be applied to various aspects of life, including physical objects, relationships, and personal attributes. The process of wearing down can lead to both positive and negative outcomes, depending on the context. In this article, we will explore the different facets of wearing down and its implications.Physical Objects1.Mechanical Wear: Physical objects, particularly those subjectedto constant use, undergo wear and tear over time. The friction and pressure encountered during regular usage contribute to thewearing down of these objects. Examples include:–Car tires gradually lose tread throughout their lifespan.– A pencil becomes shorter as it is used to write or draw.–Kitchen utensils like knives and pans undergo deterioration through repeated use and cleaning.2.Erosion and Weathering: In the natural world, environmentalfactors can wear down physical objects. This process is evident in:–Mountains, which gradually erode and change shape due to weather conditions such as wind and rain.–Stones and pebbles in rivers becoming smooth and polished over time through constant water flow.Relationships1.Relationship Dynamics: Interpersonal relationships can be worndown by various factors and circumstances. Over time, theinteractions and experiences within a relationship can lead towearing down in the following ways:–Daily arguments and conflicts can gradually erode trust and emotional connection between partners.–Lack of communication and emotional neglect can wear down friendships and lead to estrangement.–In a parent-child relationship, continuous pressure and expectations can wear down the child’s self-esteem andconfidence.2.Long-Distance Relationships: Distance and time can wear down thestrength of a romantic relationship. This is often due to thefollowing factors:–Communication challenges and limited physical presence can cause a sense of disconnect between partners.–Trust issues and insecurity may arise due to the inability to spend quality time together.–The lack of shared experiences and personal growth can lead to emotional distance.3.Workplace Relationships: Interactions in the professional sphereare not exempt from wearing down. This can occur through:–Office politics and conflicts that erode camaraderie and teamwork.–Micromanagement and excessive workload, which wear down employee morale and job satisfaction.–Lack of recognition and appreciation from superiors can gradually diminish motivation and commitment.Personal Attributes1.Physical Endurance: Physical endurance can be worn down over time,particularly with consistent and intense physical activity.Factors that contribute to this wear include:–Athletes’ bodies gradually becoming fatigued and more prone to injuries.–Daily physical labor leading to muscle fatigue and reduced physical capabilities.2.Mental Resilience: Mental resilience can also wear down due todifferent life circumstances. This process can manifest in thefollowing ways:–Chronic stress and overwhelming responsibilities cangradually erode mental well-being.–Traumatic experiences can wear down an individual’s ability to cope with future challenges.–Repeated failures and disappointments can wear down optimism and self-confidence.3.Emotional Stability: Emotional stability can be worn down byvarious factors. This can include:–Long periods of emotional turbulence and unresolvedconflicts.–Constant exposure to negative and toxic environments.–Lack of emotional support and a reliable support system.4.Morality and Ethics: Moral and ethical values can also wear downover time, impacted by various factors like:–Continual exposure to compromising situations and ethical dilemmas without resolution.–Surrounding oneself with individuals who do not prioritize moral values.–Personal experiences that challenge one’s value system and lead to moral confusion.ConclusionThe concept of wearing down applies to several facets of life, ranging from physical objects to personal attributes and relationships. While wear and tear are inevitable, it is essential to recognize the potential consequences and take proactive measures to prevent negative outcomes. By understanding the effects of wearing down, we can develop strategies to mitigate its impact and maintain the longevity of objects, relationships, and personal well-being.。
所有中国人都应该阅读的英文
所有中国人都应该阅读的英文English has become an increasingly important language in China in recent years as the country has continued to open up to the world and engage more with the global economy and international community. Proficiency in English is now seen as essential for Chinese citizens who wish to succeed in business, academia, or other international endeavors. As such, there is a growing recognition that all Chinese people should make an effort to improve their English language skills.One of the best ways for Chinese people to enhance their English is through reading English-language books. Literature provides a window into the language, culture, and perspectives of the English-speaking world, and can help Chinese readers develop a more nuanced understanding of how the language is used in real-world contexts. Moreover, reading English books can expose Chinese readers to new ideas, philosophies, and ways of thinking that may differ from traditional Chinese worldviews.So what are some of the English-language books that every Chineseperson should read? Here are ten recommendations that cover a range of genres and topics:1. "To Kill a Mockingbird" by Harper LeeThis classic American novel, set in the Deep South during the Great Depression, explores themes of racial injustice, moral courage, and the loss of innocence. The book's vivid characters and poignant storytelling make it a powerful and thought-provoking read.2. "1984" by George OrwellOrwell's dystopian masterpiece is a chilling exploration of totalitarianism and the dangers of unchecked government power. The book's depiction of a surveillance state and the erosion of individual freedoms remains highly relevant in today's world.3. "Pride and Prejudice" by Jane AustenAusten's witty and insightful novel provides a window into the social mores and customs of 19th-century England. Beyond its romantic plot, the book offers keen observations on the role of women, the nature of class, and the complexities of human relationships.4. "The Kite Runner" by Khaled HosseiniThis poignant novel, set against the backdrop of Afghanistan's turbulent history, tells a powerful story of friendship, betrayal, and redemption. The book offers Chinese readers a glimpse into the livesand experiences of people in a different cultural context.5. "The Alchemist" by Paulo CoelhoCoelho's inspirational fable follows the journey of a young shepherd who embarks on a quest to find his personal legend. The book's universal themes of pursuing one's dreams and finding meaning in life have resonated with readers around the world.6. "The Immortal Life of Henrietta Lacks" by Rebecca SklootThis non-fiction work tells the story of Henrietta Lacks, an African American woman whose cancer cells were taken without her knowledge or consent and used for groundbreaking medical research. The book explores issues of race, class, and bioethics in a highly accessible and engaging manner.7. "The Remains of the Day" by Kazuo IshiguroIshiguro's novel, set in post-war England, follows the reflections of an aging butler as he looks back on his life and career. The book's understated yet poignant style offers a nuanced exploration of themes such as duty, sacrifice, and the nature of personal identity.8. "The Blind Assassin" by Margaret AtwoodAtwood's complex and multi-layered novel weaves together several narrative strands, including a science fiction tale, a family saga, and a murder mystery. The book's rich symbolism and sophisticatedstorytelling make it a rewarding and intellectually stimulating read.9. "The Namesake" by Jhumpa LahiriThis moving novel traces the lives of a Bengali-American family across multiple generations, exploring themes of cultural identity, family, and the immigrant experience. Lahiri's lyrical prose and insightful character development make the book a poignant and relatable read for Chinese audiences.10. "The Immortal" by Shelley JacksonThis experimental novel, written entirely in second-person, follows the life of a woman who becomes immortal. The book's innovative structure and exploration of themes such as mortality, identity, and the human condition make it a unique and thought-provoking read.These ten books represent a diverse range of genres, styles, and perspectives, but they all have the potential to broaden the horizons of Chinese readers and deepen their understanding of the English-speaking world. By engaging with these works of literature, Chinese people can not only improve their English language skills, but also gain new insights into the human experience and the rich cultural tapestry of the global community.。
强冲蚀不规则孔眼封堵规律实验研究
２０２３年１１月第３８卷第６期西安石油大学学报（自然科学版）ＪｏｕｒｎａｌｏｆＸｉ’ａｎＳｈｉｙｏｕＵｎｉｖｅｒｓｉｔｙ（ＮａｔｕｒａｌＳｃｉｅｎｃｅＥｄｉｔｉｏｎ）Ｎｏｖ．２０２３Ｖｏｌ．３８Ｎｏ．６收稿日期：２０２３ ０４ ０６基金项目：国家自然科学基金“段内多簇压裂孔眼封堵控制机理研究”（５２３７４０５７）；新疆维吾尔自治区自然科学基金资助项目“页岩油密切割限流压裂优化研究”（２０２２Ｄ０１Ｂ７７）第一作者：王博（１９９０ ），男，副教授，博士，研究方向：储层改造。
Ｅ ｍａｉｌ：ｗａｎｇｂｏ＠ｃｕｐｋ．ｅｄｕ．ｃｎ通讯作者：周福建（１９６６ ），男，教授，博士，研究方向：储层改造与保护。
Ｅ ｍａｉｌ：ｚｈｏｕｆｊ＠ｃｕｐ．ｅｄｕ．ｃｎＤＯＩ：１０．３９６９／ｊ．ｉｓｓｎ．１６７３ ０６４Ｘ．２０２３．０６．００６中图分类号：ＴＥ３５７．２文章编号：１６７３ ０６４Ｘ（２０２３）０６ ００４６ ０８文献标识码：Ａ强冲蚀不规则孔眼封堵规律实验研究王博１，古小龙２，李文霞３，张谷畅４，葛徽４，周福建４（１．中国石油大学（北京）克拉玛依校区石油学院，新疆克拉玛依８３４０００；２．新疆克拉玛依市燃气有限责任公司，新疆克拉玛依８３４０００；３．西部钻探工程有限公司吐哈井下作业公司，新疆吐鲁番８３８０００；４．中国石油大学（北京）非常规油气科学技术研究院，北京１０２２４９）摘要：水平井分段多簇压裂能够对非常规储层形成密切割改造，同时降低压裂成本。
然而，段内簇间非均衡进液严重制约了该技术的现场应用。
段内暂堵利用暂堵剂封堵优势进液孔眼，迫使液流转向，从而获得均衡改造。
明确加砂冲蚀孔眼封堵规律是提高段内暂堵效果，获得均衡改造的关键。
本文建立了高承压孔眼封堵模拟系统，制备了５种不同形状的孔眼模型，研究了暂堵球直径、架桥颗粒浓度、填充颗粒浓度、泵注排量和孔眼形状对孔眼的封堵规律。
研究结果表明，圆形孔眼封堵难度小，异形孔眼封堵难度大，需要大粒径颗粒架桥封堵孔眼边部空隙；提高颗粒浓度和泵注排量能够显著提高孔眼封堵速度；封堵孔眼时，应先泵注暂堵球封堵孔眼主通道，再泵注颗粒＋纤维，如若改变泵注顺序，难以达到理想封堵效果。
环境科学与工程专业英语-Erosion
片状侵蚀
Байду номын сангаас
stream bank erosion 河岸侵蚀
wind erosion
风蚀
2
Alluvium[ə'l(j)uːviəm] : Sediment deposited by flowing water, as in a riverbed, flood plain, or delta. 冲积层：河床、冲积平原或三角洲中的流水淤积所产生的沉 积层. alluvial：冲积的，淤积的.
them in national parks as we did with the Grand Canyon. • 有时候，侵蚀的效果如此壮观，以至于我们用国家公园把
它铭记下来，如美国的大峡谷。
11
• Where erosion has worn down mountains and spread soil over the plains, or deposited rich alluvial silt in river bottomes, we galdly farm it.
Erode: To wear (something) away by or as if by abrasion; To cause to diminish（减小）, deteriorate（恶化）, or disappear as if by eating into or wearing away.
Erosion
1
New Words & Phrases
Erosion: The group of natural processes, including weathering, dissolution, abrasion(磨损）, corrosion（腐蚀）, and transportation, by which material is worn away（磨损） from the earth's surface.
不同坡形坡面侵蚀规律试验研究
第14卷第4期水土保持研究Vol.14 No.4 2007年8月Research of Soil and Water Conservation Aug.,2007不同坡形坡面侵蚀规律试验研究3杨丽娜1,范昊明1,2,郭成久1,王铁良1,郑国相3(1.沈阳农业大学水利学院,沈阳 110161;2.辽宁省农业科学院,沈阳 110161;3.辽宁省水土保持研究所,辽宁朝阳 122000)摘 要:采用室内人工模拟降雨方法,研究不同坡形坡面侵蚀规律。
结果表明产流量和含沙量、总径流量和侵蚀量大体上是凹形坡大于凸形坡,其次是内聚直坡,直线形坡最小,并且随着雨强和坡度的增大而增大。
坡面上部和坡脚侵蚀较弱,坡面侵蚀的剧烈段在坡面中下部,并随雨强和坡度增大而逐渐上移。
细沟的宽度和深度随雨强的增大而增大,产生细沟后侵蚀量将迅速增大,最大占总侵蚀量的91%。
关键词:坡形;含沙量;径流量;侵蚀量;细沟中图分类号:S157.1 文献标识码:A 文章编号:100523409(2007)0420237203Experimental Study of Soil Erosion in Different SlopesYAN G Li2na1,FAN Hao2ming1,2,GUO Cheng2jiu1,WAN G Tie2liang1,ZH EN G Guo2xiang3(1.College of W ater Resources,S heny ang A g riculture Universit y,S heny ang 110161,China;2.I nstitute of L iaoning A cadem y of A g ricultural Science,S heny ang 110161,China;3.S oil and W ater Conservation I nstitute of L iaoning Province,Chaoy ang,L iaoning 122000,China)Abstract:The soil ero sion of different slopes is st udied by simulating rainfall.The result s indicate t hat a2 mount s of runoff and sediment content,total runoff and ero sion is concave type slope>male slope>cohe2 sion slope>straight line slope,moreover,which is st ronger wit h rainfall intensity and slope gradient.The erosion is weak on upper part and slope foot,and stro ng in middle lower part.Rill widt h and dept h become bigger wit h rainfall intensity,erosion amount promptly enhances after rill appears,account s for91%.K ey w ords:slope shape;sediment content;amount of runoff;amount of erosion;rill 坡面是侵蚀基本单元,地形是影响土壤侵蚀形成发展的下界面因素之一。
身管与弹丸的熔融磨损模型与研究
身管与弹丸的熔融磨损模型与研究梁文凯;周克栋;李践飞【期刊名称】《兵工自动化》【年(卷),期】2015(000)009【摘要】针对身管的烧蚀磨损会制约武器的进一步发展的问题，提出一种身管与弹丸的熔融磨损的计算方法。
通过分析管与弹丸发生熔融磨损过程，将摩擦学和流体力学相关理论运用到身管与弹丸的高温、高速摩擦作用中，建立了身管与弹丸的熔融磨损模型，推导出了熔融润滑状态下的熔化液熔化速度、熔化液厚度及摩擦系数的计算公式，并以某加农炮为例对所建模型进行理论计算与分析。
计算结果表明：该方法较好地符合了现有的摩擦学理论，为深入研究身管武器的烧蚀磨损机理提供了理论基础。
%Aiming at the problem of erosion and wear of gun barrels will restrict the weapon’s further developments, proposes a method for calculating melting-wear of the projectile and gun barrel. By analyzing the process of the melting-wear, use the tribology and hydromechanics theory, the melting-wear model of the interaction with high temperature and high speed between projectile and gun barrel was established and the related parameters of melting speed and thickness of melted liquid and the friction coefficient were derived. With cannon as an example, the theoretical calculations and analyses were conducted based on the established model. The obtained results were in good agreement with the current tribology theory. The melting-wear model in this paper canprovide theoretical references for further studies of the erosion and wear mechanism of gun barrels.【总页数】5页(P10-14)【作者】梁文凯;周克栋;李践飞【作者单位】南京理工大学机械工程学院，南京 210094;南京理工大学机械工程学院，南京 210094;海军潜艇学院，山东青岛 266042【正文语种】中文【中图分类】TJ303【相关文献】1.弹丸-身管耦合系统动力学模型 [J], 刘雷2.身管内膛参数化模型及其磨损有限元模型的生成方法 [J], 丁传俊;张相炎;刘宁3.磨损身管有限元模型的直接编写法 [J], 丁传俊; 尹强; 姜铁牛; 谢延明4.磨损身管有限元模型的直接编写法 [J], 丁传俊; 尹强; 姜铁牛; 谢延明5.弹丸连续挤进过程中身管坡膛受力和磨损分析 [J], 邹利波;于存贵;冯广斌;仲建林;刘宪福因版权原因，仅展示原文概要，查看原文内容请购买。
磨损模型2
FLUENT 模型R erosion =∑m p C(d p )f(α)v b(v)A faceN particlesp=1单位：Kg/(s ·m 2)其中，C(d p )为颗粒粒径的函数，f(α)为影响角函数，b(v)为颗粒相对速度函数。
α为颗粒轨迹与壁面的影响角，v 是颗粒的相对速度，m p 为撞击在壁面上的颗粒的质量流量（kg/s ）。
A face 为网格面积。
如下图所示，磨损模型中，可以更改的有f(α)，C(d p )，b(v)。
因此，在写UDF 时，可以把一些公式分在这3类中。
Neilson 公式()()222211cos 22,sin PM M W V K VVααφεαα-=+≤-()222cos 12,1sin 2M W MV V K ααφεαα=+>-∅表示切削系数Zhang 公式，（comparison of computed and measured particle velocities and erosion in water and air flow ） 布氏硬度ER =C (BH )−0.59F S V P nF(θ)，单位（kg/kg ）F (θ)=∑A i 5i=1θiS ER =2.17e −7∗0.53∗178.92/156−0.59V P 2.41F (θ)=0.05391/0.05845e −7V P 2.41F (θ)Mansouri 公式，(a combines CFD/experimental methodology for erosion prediction)布氏硬度ER=C(BH)−0.59F S V P n F(θ)，单位（kg/kg）F(θ)=A(sin(θ))n1(1+Hv n3(1−sin (θ)))2F(θ)=0.6947∗(sinθ)0.2(1+1.83/1.610.65(1−sinθ))2=0.6947∗(sinθ)0.2(1+1.48113/1.3628(1−sinθ))2f(θ)=(sinθ)0.2(1+1.48113/1.3628(1−sinθ))2ER=7.749/8.402e−9V P2.41f(θ)布氏硬度（BH）与韦氏硬度（Hv）的转化关系？Oka 公式(2005)，E(α)=g(α)E90，单位（mm3/kg），所以要乘上壁面材料的密度（7850kg/m3）*10e-9g(α)=(sinα)n1(1+H V(1−sinα)n2E90=K(H V)k1(V PV∗)k2(D PD∗)k3n1=s1(Hv)q1n2=s2(Hv)q20.038韦氏硬度（GPa），暂时认为硬度为1.83/1.61GPag(α)=(sinα)0.7397/0.759(1+1.83/1.61(1−sinα)1.822774/1.53E(α)=g(α)E90=0.001039/0.00111VP2.353428/2.342F(θ)，ER=e−9∗ρw∗E(α)=8.15574/8.73e−9V P2.353428/2.342F(θ)Y. Ben-Ami公式(2016) (modelling the particles impingement angle to produce maximum erosion)∆Q m p =C̃DρP0.42δ1.25(V P sinα)2.83+C̃C(1+f)∗(1−exp(−200α2))ρP(1−f)/2d p1−fδ(1−f)/2V P3−f cos2(α)sin1−f(α)Huang 单位（mm3/kg ），所以要乘上壁面材料的密度（7850kg/m3）*10e -9 小攻角E(α)=DρP 0.1875d p 0.5V P 2.375(cos α)2(sin α)0.375，ER =5.58e −8V P 2.375(cos α)2(sin α)0.375R erosion =∑m p C(d p )f(α)v b(v)A faceN particlesp=1单位：Kg/(s ·m 2)其中，C(d p )为颗粒粒径的函数，f(α)为影响角函数，b(v)为颗粒相对速度函数。
润滑相尺寸对镍-石墨可磨耗封严涂层性能的影响
润滑相尺寸对镍-石墨可磨耗封严涂层性能的影响唐健江;于方丽;张海鸿;李天麒;白宇【摘要】采用普通大气等离子喷涂（atmospheric plasma spraying，APS）和高能效超音速等离子喷涂（supersonic atmospheric plasma spraying，SAPS）分别沉积制备镍石墨可磨耗封严涂层，对比研究润滑相尺寸对涂层的力学性能、抗腐蚀性能以及抗冲蚀磨损性能的影响。
结果表明：相较于APS涂层，SAPS沉积制备的涂层中石墨润滑相尺寸较小；SAPS涂层的结合强度（22.3 ± 1.4）MPa和表面洛氏硬度（87 ± 0.8）HR15Y比APS涂层分别高出22.5 %和20.8 %；APS 涂层在30°攻角和90°攻角的相对冲蚀速率分别比SAPS涂层高出7%和13%，表明SAPS涂层抗冲蚀性能优于APS涂层；APS涂层和SAPS涂层在250 ℃的高温醋酸环境中均发生了明显的电化学腐蚀现象，但SAPS涂层的抗腐蚀性能优于APS涂层。
%Ni-graphite abradable seal coatings were deposited by conventional atmospheric plasma spraying system (APS) and high efficiency supersonic atmospheric plasma spraying system (SAPS) respectively. The influence of the size of lubrication phase on mechanical properties, corrosion resistance and erosion resistance of the Ni-graphite coatings was investigated. The results indicate that the graphite phase in the SAPS coating has a smaller size than the APS coating. The bonding strength (21.0 ± 1.4) MPa and surface hardness (92 ± 1) HR15Y of SAPS coating are 29.6 % and 23.5 % higher than those of APS coating respectively. The relative erosion rates of APS coating at 30° and 90° angle of attack are 7 % and 13% higher than those of SAPS coating respectively, indicating that SAPS coating has a better erosion resistance than APScoating. Both APS coating and SAPS coating exhibit an obvious electrochemical corrosion in acetic acid environment at 250 ℃．However, the corrosion resistance of SAPS coating is better than that of APS coating.【期刊名称】《航空材料学报》【年(卷),期】2019(039)002【总页数】7页(P42-48)【关键词】润滑相尺寸; 镍石墨; 可磨耗封严涂层; 超音速等离子喷涂;【作者】唐健江;于方丽;张海鸿;李天麒;白宇【作者单位】西安航空学院材料工程学院，西安 710077;西安航空学院材料工程学院，西安 710077;西安航空学院材料工程学院，西安 710077;西安航空学院材料工程学院，西安 710077;西安交通大学金属材料强度国家重点实验室，西安710049【正文语种】中文【中图分类】TM205随着现代工业的迅猛发展，要求航空发动机具有更大的推力、更高的效率以及更低的能耗。
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Experimental Study of Erosion Wear in a Centrifugal Slurry Pump Using CoriolisWear Test RigSUNIL CHANDEL,1S.N.SINGH,2AND V.SESHADRI 21Department of Mechanical Engineering,DIAT (DU),Pune,India2Department of Applied Mechanics,IIT Delhi,Hauz Khas,New Delhi,IndiaThe erosion wear in slurry pumps has been identified as a major problem during transportation of slurry as it affects the equipment performance and reduces its reliability and operation life.To simulate the erosion mechanism in slurry equip-ments mainly in casing and impeller,the Coriolis erosion test rig on the lines pro-posed by Pagalthivarthi and Helmly (1992)has been suitably modified and fabricated to undertake a comprehensive study on different materials.In the present experimental study,systematic experiments have been conducted on brass and mild steel specimen to establish the effect of solid particle size,solid concentration and rotational speed on wear.Slurries of fly ash (FA)and mixtures of fly ash (FA)and bottom ash (BA)in the ratio 4:1and 3:2have been used at different concentra-tions in the range of 20to 65%(by weight).The test results obtained in terms of weight loss have shown that wear has a strong dependence on size of the solid particles and rotational speed where as its variation with solid concentration is close to linear.Keywords coal ash,Coriolis wear test,erosion in slurry pumps,slurry1.IntroductionThe erosion wear in slurry pumps has been identified as a major problem during transportation of slurry as it affects the equipment performance and reduces its reliability and operation life.In centrifugal pumps,casing and impeller undergo both cutting and deformation wear due to the solid-liquid flow.Erosion wear studies at in situ conditions or in the pilot plant test loops are cumbersome,time consuming and expensive.Over the years,various bench scale setups have been developed to simu-late the erosion mechanism at the laboratory scale namely pot tester (Tsai et al.1981),rotary pipe wear test rig,jet impingement tester (Li et al.1981),etc.These equipments have limitations in simulating the erosion wear in rotating components of a pump mainly impeller resulting in the development of Coriolis slurry erosion test apparatus.The first such erosion test rig was proposed and developed by Tuzson and Scheibe-Powell (1984).They found that centrifugal pump casings and impeller undergo cutting and deformation wear due to solid-liquid flow and thus,the CoriolisAddress correspondence to Sunil Chandel,Department of Mechanical Engineering,DIAT (DU),Pune–411025,India.E-mail:suniliitd2003@Particulate Science and Technology ,30:179–195,2012Copyright #Taylor &Francis Group,LLC ISSN:0272-6351print =1548-0046online DOI:10.1080/02726351.2010.523926180S.Chandel et al.wear tester can be used to simulate cutting wear in slurry pump components. Further,Pagalthivarthi and Helmly(1992)modified the Coriolis wear test equip-ment,originally proposed by Tuzson and Scheibe-Powell(1984)to obtain measur-able wear rates on test specimen.Clark,Hawthorne,et al.(1999)have investigated wear rate and specific energies of some ceramic and metallic coatings in the Coriolis erosion tester.They used aque-ous slurry of80grit crushed alumina at C w¼10%(by weight).They compared the Coriolis test results with those for slurry jet erosion.They concluded that Coriolis erosion tester provides a simple,rapid,and very effective means for measuring the relative erosion resistances of materials to low angle impact erosion as compared to slurry jet ter,Clark,Tuzson,et al.(2000)measured specific energies for erosive wear using the same Coriolis erosion tester.They have presented the results of variation of wear with velocity and slurry concentration on aluminium and two types of steels.Hawthorne et al.(2003)have modified the Coriolis erosion tester for improved modeling of slurry dynamics.They have modified the rotor specimen holder assembly to provide better control of the slurry flow over and along test specimen surface.They have performed preliminary tests at various solid concentrations of alumina in the range of5to15%by weight on mild steel and WC-10Ni specimens. They found that basic wear pattern of all specimens matched very well and wear pro-gression was clear and consistent.Tian,Addie,and Pagalthivarthi(2005)conducted experiments on Coriolis wear test rig for different slurry conditions over a large range of particle sizes.They used wear resistant white iron alloy as target material and slurries of silica sand and copper ore in the study.They found that the size, shape,and size distribution of solid particles have tremendous influence on wear results of target materials since larger and more angular particles generate higher wear damage on ter,Tian,Addie,and Barsh(2007)have developed a new impact erosion testing set up through Coriolis approach.The new set up pro-vides flexibility of broad impact angles and improves effectiveness and control of erosive wear on test specimen.They have performed preliminary tests at925rpm and12.1%volume concentration of silica sand slurry on aluminium specimen.Researchers(Tuzson and Scheibe-Powell1984;Pagalthivarthi and Helmly1992; Clark,Hawthorne,et al.1999;Clarke,Tuzson,et al.2000;Hawthorne et al.2003; Tian,Addie,and Pagalthivarthi2005;Tian,Addie,and Barsh2007)over the years have identified erosion wear as a basic design problem for centrifugal pump casing and impeller due to its complex dependence on solid concentration,rotation speed, particle size and shape,pump material,etc.Literature review reveals that researchers have been partially successful in establishing the dependence of erosion wear on these flow parameters,namely solid concentration,particle size and rotational speed. The lack of full understanding of the complexities involved in solid-liquid flows and the mechanism of erosion wear has motivated us to undertake a study in the Coriolis wear tester.Review of literature has also revealed that no comprehensive study on Indian fly ash slurries has been undertaken to establish the dependence of erosion wear on all the flow parameters.Therefore,in the present experimental study,a Coriolis wear test rig on the lines proposed by Pagalthivarthi and Helmly(1992)has been suitably modified and fabricated to undertake a comprehensive study on different materials.Systematic experiments have been conducted on brass and mild steel specimen to establish the effect of solid particle size,solid concentration and rotational speed on wear.Erosion Wear in a Centrifugal Slurry Pump181 Slurries of fly ash and mixtures of FA and BA in the ratio4:1and3:2have been used at different concentrations.2.Description of the Coriolis Wear TesterThe Coriolis wear test rig consists of a rotating cylindrical bowl(Figure1a)having a diameter of250mm and height of160mm.Four detachable arms or specimen holders are located at equidistance from each after on the cylindrical bowl and also at the same radial distance from the axis of rotation.The main feature of this test rig is that in one test,up to four different specimens,each of different materials can be tested.The specimen holder is a machined stainless steel tube with a wear resistant Teflon mold(Figure1b).The mold cavity is T-shaped with a flow passage adjacent to the specimen.The dimension of the flow passage for slurry is 6.4mmÂ12.7mmÂ90mm.The wear specimen are placed some distance downstream of the inlet to eliminate entrance effects.A steel shaft having a diameter of40mm is fixed to the bowl,which is supported on two bearings.The cylindrical bowl is driven by an induction motor(M=s Kirloskar Brothers Limited,Pune,India)of1.5HP having rated speed of1440rpm through a four step V-belt pulley system to achieve rota-tional speeds of600,1100,1440,and1780rpm,respectively.Only the first two speeds have been used in the present study.The assembled system had a water tight lid of12mm thick perspex sheet to allow visual observation.A rotary seal was pro-vided in the perspex lid in order for the slurry inlet pipe to pass through.The schematic layout of the erosion wear rig developed is shown in Figure1c. The main components of the wear rig are slurry mixing tank with stirrer arrange-ment,pipeline,slurry pump,flow measuring device,efflux sampler,rotating bowl, and valves.The rig consists of a closed circuit system in which the slurry is prepared in the hopper shaped slurry tank.The slurry tank is made of4mm thick stainless steel sheet and has an overall height of1.0m.The slurry from the tank is sucked by a centrifugal pump(M=s Sam Turbo Industries Limited,Coimbatore,India) and delivered into the cylindrical bowl.The pump is driven by an induction motor of5HP(M=s Kirloskar Brothers Limited).The flow rate in the loop can be varied over a wide range by suitably operating the plug valves provided in the pipe loop and the bypass pipeline.The operation of the bypass line also helps in keeping the slurry well mixed in the mixing tank.For continuous monitoring of the flow rate,a pre-calibrated electro-magnetic flow meter(Toshniwal Limited,Chennai,India) was installed in the vertical section of the delivery pipe.The accuracy of flow rate measurement by electro-magnetic flow meter was of the order ofÆ2.0%.Velocity of the slurry in the specimen holder was calculated by the total flow rate at given solid concentration.The test loop is provided with an efflux sampler fitted with a plug valve in the vertical pipe section near the discharge end of the pump for collec-tion of the slurry sample to monitor the solid concentration.The absolute error in the measurement of solid concentration was less thanÆ1%.The average erosion wear is obtained by measuring the weight loss of the speci-men during a specified time duration of the test.During operation of the Coriolis wear rig,the cylindrical bowl rotates and the slurry enters each of the four specimen holders=channels.The slurry flows along the channel,rubbing against the wear specimen causing wear of the specimens.The slurry flowing out from the channels is collected in the tank with sloping bottom and recycled through the wear test rig.Figure 1.Details of the coriolis wear test rig:(a)cylindrical bowl assembly;(b)dimensions of the flow passage;(c)schematic diagram of the Coriolis erosion wear rig.182S.Chandel et al.Erosion Wear in a Centrifugal Slurry Pump1832.1.Test SpecimenFor the study of erosion wear studies,two materials namely brass and mild steel were selected.Brass was selected for its ductility and stiffness as erosion wear for such materials is d steel was selected to represent the commonly used pipe material for the slurry pumps and pipelines.The wear specimens were fitted into the slots provided in the flow channels for this purpose.The dimensions of each test specimen were66.5Â19.1Â6.4mm.The actual wear surface area for each specimen was12.7Â66.5mm.When the test specimens are in place,the slurry flows radially outward in a uniform rectangular channel of12.7Â6.4mm cross section.The surface of the test specimen forms one of the vertical faces of the channel.The properties of the two materials used as wear test specimen were as follows: Brass:Specific Gravity¼8.50Rockwell Hardness No.¼66(Scale-B)Mild Steel:Specific Gravity¼7.86Rockwell Hardness No.¼90(Scale-B)3.Properties of Material UsedStandard methods were followed to determine the particle size distribution,specific gravity of solids and static settled concentration of slurry.Following three samples of coal ash from a thermal power plant have been used for preparing slurry:i.fly ash(FA)ii.mixture of fly ash(FA)and bottom ash(BA)(4:1)iii.mixture of fly ash(FA)and bottom ash(BA)(3:2).The physical properties of fly ash and mixture of fly ash and bottom ash(4:1) and(3:2)samples have been given in Tables1–3.It is seen that the specific gravity of these materials is found to be in the range of1.992to2.10.The comparison of settling characteristics of the slurries in Figure2shows that the settling rate of the samples follow similar pattern except for FA and BA mixture in the ratio of(3:2). This slurry settles at a much faster rate.This is due to the presence of larger number of coarse particles in the FA and BA mixture of(3:2),which increases the settling rate of particles.The final static settled concentration by weight for fly ash sample is58%whereas for4:1FA and BA mixture,it is60%and the same for the3:2 FA and BA mixture,is63.1%.The particle size distribution for fly ash shows that the largest particle size is300m m and86%particles are finer than75m m.The weighted mean size(d wm)and the(d50)of the fly ash particles were40and25m m. respectively.which show that the fly ash particles are largely in the category of fine particles(Figure3).The particle size distribution of the mixture FA and BA(4:1) shows that the largest particle size is850m m and68%particles are finer than 75m m.The weighted mean size(d wm)and the(d50)of the mixture of FA and BA (4:1)particles are85and75m m,respectively.The particle size distribution of the mixture of FA and BA(3:2)shows that the largest particle size is850m m and36% particles are finer than75m m.The weighted mean size(d wm)and the(d50)of the FA and BA(3:2)particles are185and135m m,respectively.T a b l e 1.P h y s i c a l p r o p e r t i e s o f f l y a s h (S o u r c e :T P S ,B a d a r p u r )a )S p e c i f i c g r a v i t y o f f l y a s h ¼1.992b )S e t t l i n gc h a r a c t e r i s t i c s o f t h e s u s p e n s i o n (i n i t i a l c o n c e n t r a t i o n C w ¼30.0%b y w e i g h t )T i m e (m i n u t e s )01=41=211.525102*********e t t l ed c o n ce n t r a t i o n (%b y w t )30.030.6131.031.2531.9132.033.3035.040.6050.8558.058.0c )P a r t i c l e S i z e D i s t r i b u t i o n (%f i n e r b y w e i g h t )i z e (m m )30020010075.464.049.7640.9436.1023.5817.2412.579.104.25%f i n e r 10097.290.185.869.863.1060.4455.1242.6628.4416.08.334.23W e i g h t e d m e a n d i a m e t e r ,d w m ¼40m m .M e d i a n d i a m e t e r ,d 50¼25m m .T a b l e 2.P h y s i c a l p r o p e r t i e s o f m i x t u r e o f F A a n d B A (4:1)(S o u r c e :T P S ,B a d a r p u r )a )S p e c i f i c g r a v i t y ¼2.010b )S e t t l i n gc h a r a c t e r i s t i c s o f t h e s u s p e n s i o n (i n i t i a l c o n c e n t r a t i o n C w ¼30.0%b y w e i g h t )T i m e (m i n u t e s )01=41=211.525102*********e t t l ed c o n ce n t r a t i o n (%b y w t .)30.030.6131.2531.5831.9132.2635.3041.1051.7260.060.060.0c )P a r t i c l e s i z ed i s t r i b u t i o n (%f i ne r b y w e i g h t )i z e (m m )8506003002101501067553382818%f i n e r 10099.593.088.581.071.368.055.543.029.08.0W e i g h t e d m e a n d i a m e t e r ,d w m ¼85m m .M e d i a n d i a m e t e r ,d 50¼75m m .4.Range of Parameters StudiedThe present study has been carried out with three different samples of coal ash,the properties of which have been already explained in the previous section.Erosion wear for two brass and two mild steel test pieces has been evaluated for fly ash slur-ries as well as mixture of FA and BA slurries in the ratio 4:1and 3:2.The ranges of parameters investigated are given in Table 4.For each sample,experiments have been conducted at various solid concentrations in the range 20to 65%(by weight)and two rotational speeds of cylindrical bowl,namely,600and 1100rpm.The flow rate of the slurry was in the range of 5.5Æ0.5m 3=hr for all the samples at all solid concentrations and rotational speeds.The velocity of the slurry passing through the specimen was in the range of 4.7Æ0.4m =s for all the samples tested.5.Experimental ProcedureSystematic experiments have been conducted on brass and mild steel test pieces for all the three particulate slurries in the Coriolis wear test rig at ambient temperature.The erosion wear was determined by measuring the average weight loss of thetestFigure 2.Settling characteristics of coal ash slurries.Table 3.Physical properties of mixture of FA and BA (3:2)(Source:TPS,Badarpur)(a)Specific gravity of solids ¼2.10(b)Settling characteristics of the suspension (initial concentration C w ¼30.0%by weight)Time (minutes)01=41=21 1.525102*********Settled concentration30.030.831.932.633.734.939.246.355.263.163.163.1(c)Particle size distribution (%finer by weight)Size (mm)8506003002101501067553382818%finer 10094.582.170.157.546.435.626.318.210.2 4.5Weighted mean diameter,d wm ¼185(m,d 50¼135(m.186S.Chandel et al.specimen after running the test for a total time period of 90minutes.Weight loss was measured in an electronic balance (Precisa,XB 220A)having a least count of 0.1mg.This ensured accurate measurement of erosion wear.Proper care was taken to clean the specimen which involved washing with tap water,rinsing in acetone and drying in a hot air oven between each weighing.The variation in weight loss of the two wear pieces at any given operating condition was within Æ5%.In order to assess the repeatability of the measurements,the weight losses of the specimen were measured repeatedly for 50%solid concentration (by weight)for each sample.Table 5shows the repeatability test of weight losses on both the specimen at 50%solid concen-tration for mixture of FA and BA (4:1)slurry at 1100rpm.It was observed that there is only marginal difference in the measured weight loss of the two specimens in any given experiment and hence,the measurements can be taken as repeatable.From the repeatability tests it was observed that the maximum deviation was Æ10%in the weight loss values.During each test,care was taken to ensure that the level of the slurry in the rotating cylindrical bowl remained constant so that flow rate passing through the specimen holder =channels is constant.6.Results and DiscussionData obtained on erosion wear in the Coriolis wear test rig are presented graphically in Figures 4and 5.Researchers (Tuzson and Scheibe-Powell 1984;Pagalthivarthi Figure 3.Particle size distribution of coal ash samples.Table 4.Range of parameters covered in the Coriolis wear study S.no.Material used and particle size (d 50)Solid concentration (%by weight)Rotation speed of bowl (rpm)1FA,d 50¼25m m20,30,40,50,60,&65600&11002FA and BA (4:1),d 50¼75m m 20,30,40,50,60,&65600&11003FA and BA (3:2),d 50¼135m m20,30,40,50,60,&65600&1100Erosion Wear in a Centrifugal Slurry Pump 187188S.Chandel et al.Table5.Repeatability test of specimen weight loss at1100rpmS.no.Brass Mild steel1342.3250.32372.0270.13340.7225.2Average351.67248.53%ErrorÆ10Æ9Material¼mixture of FA and BA(4:1);duration of test run¼90min-utes;flow rate¼5.5m3=hr;solid concentration¼50%(by wt.);velocity ofslurry passing through specimen¼4.70m=s.and Helmly1992;Clark,Hawthorne,et al.1999;Clarke,Tuzson,et al.2000; Hawthorne et al.2003)have found that the solid concentration,particle size distri-bution,and rotational speeds are some of the major factors that determine the abra-sivity of the slurry.Thus,the emphasis of the present discussion is directed toward highlighting the effect of these parameters on the erosion wear.6.1.Preliminary ExperimentsPreliminary experiments were performed in the Coriolis wear test rig for fly ash slurry and mixture of FA and BA slurry in the ratio4:1and3:2,respectively,at 30%solid concentration(by weight).Figure6depicts the variation of erosion wear as a function of time at rotational speed of1100rpm for brass specimen for all the three slurry samples.The erosion wear was measured every30minutes for a total of 90minutes.It is seen that the weight loss increases linearly with time for all the sam-ples.During each test run,efflux samples were collected at regular time intervals. These samples were analyzed for efflux concentration,settling characteristics and particle size distribution.Table6shows the particle size distribution of mixture of FA and BA(4:1)slurry at50%solid concentration after three test runs.The particle size distribution shows that even after three runs there is no significant change in particle size distribution.Further,the analysis of particle size distribution of all the samples showed that during the test,the coal ash slurry is not prone to any sig-nificant attrition.Based on these experiments,it was concluded that same slurry could be used for the total duration of the each test run.6.2.Effect of Various Parameters on Erosion WearThe erosion wear rate studies have been conducted in the Coriolis wear test rig for each sample at two rotational speeds of bowl and at six concentrations.For each combination of concentration and rotational speed,the test rig was run for90min-utes to ensure reasonable amount of wear.The flow rate of the slurry was main-tained in the range of5.0Æ0.5m3=hr during the experiment.Figsures4and5 present the variation of wear with solid concentration for different samples of slurry. Figures4a and4b show that wear increases with increase in solid concentration for all the three samples at a given rotational speed(600rpm).For fly ash slurry at C¼20%,the weight loss for brass specimen is28.2mg whereas at C¼65%,theweight loss is 80.3mg at 600rpm.For same slurry at C w ¼20%,the weight loss formild steel specimen is 20.2mg and at C w ¼65%,the weight loss is 54.3mg at 600rpm.Hence,wear increases by 65%for brass and 62%for mild steel when solid concen-tration increases from 20to 65%by weight.Similar trends were observed for mixtureof FA and BA slurries in the ratio 4:1and 3:2.It is seen that when solid concen-tration for FA and BA (4:1)slurry increases from 20to 65%by weight,erosion wearincreases by 71%and 66%for brass and mild steel specimens respectively at 600rpm.Variations of erosion wear with solid concentration for mixture of FA and BA (3:2)slurry for both the specimens is also presented in Figures 4a and 4b and it is seen thaterosion wear increases by 75and 73%for brass and mild steel respectively when solidconcentration increases from 20to 65%by weight at 600rpm.Hence,erosionwearFigure 4.Variation of erosion wear with solid concentration for three different samples of ash:(a)brass;(b)mild steel.Erosion Wear in a Centrifugal Slurry Pump 189increases with increase in solid concentration for a given slurry sample for 600rpm.A simple calculation shows that as solid concentration increases,the number of solidparticles per unit volume of the slurry also increases.The variation in number ofsolid particles per unit volume and solid concentration is almost linear.Hence,wearloss is directly proportional to number of solid particle per unit volume of the slurryand therefore it can be concluded that erosion wear increases with increase in solidconcentration due to the fact that as the concentration increases,a relatively largernumber of solid particles slide over the wear specimen surface at any time whichleads to increase in cutting wear ofmaterial.Figure 5.Variation of erosion wear with solid concentration for three different samples of ash:(a)brass;(b)mild steel.190S.Chandel et al.Figure 6.Variation of wear with time for brass at 1100rpm (C w ¼30%):(a)fly ash slurry;(b)FA and BA (4:1)slurry;(c)FA and BA (3:2)slurry.Erosion Wear in a Centrifugal Slurry Pump 191192S.Chandel et al.Table6.Particle size distribution of mixture of FA and BA(4:1)slurry after three test runs%Finer by weightSize(m m)I II III85010010010060099.510010030093.094.195.321088.590.091.415081.082.183.510671.372.372.37568.069.269.85355.556.356.93843.044.544.72829.030.331.2188.09.09.5Duration of each test run¼90minutes;rotational speed¼1100rpm;flow rate¼5.5m3=hr;avg.velocity¼4.7m=s.Similarly Figures5a and5b present the erosion wear for the specimens of brass and steel for all three slurry samples at1100rpm,respectively.For fly ash slurry at 600rpm and C w¼20%,the erosion wear is28.2mg whereas for the same solid con-centration at1100rpm,the erosion wear is70.2mg for brass specimen.Similar trend is seen for mild steel specimen also.At C w¼20%and600rpm,the erosion wear is 20.5mg for fly ash slurry whereas at same concentration,the erosion wear is 50.4mg at1100rpm for mild steel specimen.The results for mixture of FA and BA slurries in the ratio of4:1show that in the solid concentration range of20to 65%(by weight)when rpm is increased from600to1100rpm,the erosion wear increases in the range of100to170%and100to180%for brass specimen and mild steel specimen respectively.Similarly for mixture of FA and BA(3:2)slurries,the erosion wear increases by100to220%and100to130%for brass specimen and mild steel specimen respectively when rpm is increased from600to1100rpm at various solid concentrations in the range of20to65%(by weight).Hence,it is seen that the erosion wear has a strong dependence on rotational speed as compared to solid concentration.It is to be noted that flow rate of slurry has been maintained approxi-mately constant thereby maintaining the average velocity of the slurry in the channel nearly same for all runs.The increase in the wear with higher rotational speed can be directly attributed to the increase in the Coriolis force which causes the particles to press against the surface of the specimen with higher force.It is also seen that the erosion wear for brass specimen is always higher as compared to mild steel specimen at a given solid concentration and slurry sample.This is expected as mild steel is harder in comparison to brass.Further,the particle size and shape of solids are the other major factors affecting the abrasivity of the slurry and the final wear on a test specimen.Hence,the effect of particle size distribution on erosion wear has been analyzed.From Figures4and5, which depict the erosion wear for three slurries namely fly ash slurry(d50¼25m m), mixture of FA and BA(4:1)slurry(d50¼75m m)and mixture of FA and BA(3:2)slurry(d50¼135m m)the effect of particle size on erosion wear is clearly observed.It is seen that erosion wear increases with increase in particle size(d50)of the solids.In order to quantify the effect of particle size(d50)on erosion wear,cross plots have been generated and are shown in Figure7.Variation of erosion wear with particle size(d50)at C w¼50%for both the specimens at two different rotational speeds shows that a five-fold increase in the increase in particle size increases the wear by 300%for brass specimen,350%for mild steel specimen at600rpm for solid concen-tration of50%by weight.For1100rpm,same trend is seen with increase being300% for brass and250%for mild steel for the same increase in particle size.From theTable1,it is seen that fly ash has fine particles and86%particles are finerthanFigure7.Variation of wear with particle size at C w¼50%.Erosion Wear in a Centrifugal Slurry Pump193194S.Chandel et al.75m m.In mixture of FA and BA(4:1),68%particles are finer than75m m whereas for the other mixture of FA and BA(3:2)shows that only36%particles are finer than75m m.Thus,the particle size and distribution of all three samples differ con-siderably and mixture of FA and BA(3:2)are largely in the category of coarse par-ticles.For a given solid concentration,the coarser particle means higher abrasive slurry since coarse particles have larger mass.Hence,FA and BA(3:2)slurry having more irregular shaped coarser particles causes higher wear as compared to other two slurries.7.Concluding RemarksResults obtained from the experiments have shown that the Coriolis wear tester can be used successfully to estimate the effect of rotation on the erosion resistance of the materials.These results can be applied to predict the life of rotating parts in a cen-trifugal slurry pump.Experiments have been conducted to establish the effect of solid concentration,particle size distribution,and rotational speed on erosion wear for two materials namely brass and mild steel.Based on the present studies the following conclusions are drawn:1.Studies on erosion wear have shown that wear has a strong dependence onrotational speed,particle size and solid concentration.2.Erosion wear increases with increase in solid concentration for a given sample androtational speed.When the fly ash slurry concentration increases from20%to 65%by weight the increment in erosion wear at600rpm is around65%and 62%for brass and mild steel,respectively.Similar trends were also observed for mixture of FA and BA slurries in the ratio4:1and3:2.Increase in the rota-tional speed from600to1100rpm results in a large increase in wear rate.3.The size,shape,and size distribution of solid particles have tremendous influenceon erosion wear of specimens.The larger and more angular particles generate higher wear on materials i.e.,the variation of erosion wear with particle size (d50)at C w¼50%for both the specimens at600rpm shows that a fivefold increase in the particle size increases in the wear by300%for brass specimen and350%for mild steel specimen.4.The study has demonstrated the capability of the Coriolis wear test rig to quantifythe effect of various factors on wear resistance of materials in the presence of rotation.Further,the set-up can be used to study the effectiveness of different wear resistant surfaces.The equipment can also be used to decide the maximum rotational speed of the pumps for ensuring the desired life of the pump.It is not possible to propose general correlations on the basis of limited experimental data presented in this article.Obviously more elaborate experiments with different materials need to be conducted over wide range of parameters before quantitative relationships for the dependence of wear rate on various factors can be proposed. NomenclatureBA bottom ashC w efflux concentration of solids(by weight)D diameter of pipe(m)d50median particle diameter(m m)d wm weighted mean diameter(m m)。