Aerodynamic optimization of a solar race car body shape (computational fluid dynamics)
信息资源检索与利用总复习题答案(部分)①
A、Site B、Filetype
C、Int的“OR”来表示逻辑“或”操作。
4. The mammalian cell as a microorganism;-genetic and biochemical studies in vitro puck, Theodore T.(Theodore Thomas) xi,219p.illus.24cm. ISBN 0-816-26980-7 San Francisco,Holden-Day 1972 该文献类型有（ ），这是独有的一个特殊查询语法。 （ D ）
A.空格 B.加号
C.括号 D.书名号
19. Luc Huyse and R.Michael, Aerodynamic shape optimization of two-dimensional airfoils under uncertain operating conditions, NASA/CR-2001-210648 ICASE Report No.2001-1 IECASE Mail Stop 132c NASA Langley Research Center Hampton,VA 23681-2199, January2001, pp.13该文献类型为科技报告。（ √ ）
13. 超星数字图书馆按《中图法》分为二十二个分馆。（ √ ）
14. 分类途径就是按照文献的名称体系查找文献的途径。（ × ）
15. 湘潭大学外文全文电子期刊导航提供刊名字顺、学科专业、来源数据库检索，并能检索免费科学搜索引擎SCIRUS。 （ √ ）
26. 请列举3个查找国外专利信息的网站名及网址（美国专利商标局专利数据库USPTO ）、（IBM公司知识产权网 ）、（RB专利数据库PAJ http://www.jpo.go.jp ）。
航空发动机专业英语之空气动力学
Introduced how to reduce the impact of emissions on aircraft performance and meet environmental regulations by optimizing exhaust emission design and control technologies.
With the continuous improvement of aircraft performance, the aerodynamic design of aircraft engines is affecting more string requirements, including higher take off and landing speeds, longer flight distances, and more complex flight conditions
Detailed description
Definition and Concepts
Understanding the characteristics and classification of fluids helps to gain a deeper understanding of the working principles of aircraft engines.
Air inlet aerodynamics
Explored the effects of aerodynamic phenomena in combustion chambers on combustion efficiency and emissions, including flame propagation speed, combustion stability, and combustion chamber outlet temperature distribution.
某型电动飞机螺旋桨的设计与试验
某型电动飞机螺旋桨的设计与试验项松;刘远强;佟刚;张利国;康桂文;吴江;王吉;刘百明【摘要】某型电动飞机采用稀土永磁电动机作为动力装置,采用螺旋桨产生拉力.为了提高电动飞机的航时,螺旋桨的设计目标应为:具有较高的效率,足够的拉力,并且保证螺旋桨需用功率与电动机功率相匹配.设计了某型电动飞机的固定桨距螺旋桨,建立了螺旋桨的三维CATIA模型,制造了两叶的木质螺旋桨,进行了螺旋桨的地面试验和风洞试验.试验结果表明:该型螺旋桨在起飞状态(螺旋桨转速2 164 r/min),静态拉力达到98.2 kg,电动机轴功率为35.09 kW,电池输出功率37.08 kW;巡航状态,螺旋桨效率达86.76％,设计的螺旋桨达到了预期的设计目标.【期刊名称】《西北工业大学学报》【年(卷),期】2016(034)003【总页数】7页(P460-466)【关键词】电动飞机;螺旋桨;高效率;地面试验;风洞试验【作者】项松;刘远强;佟刚;张利国;康桂文;吴江;王吉;刘百明【作者单位】沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136;沈阳航空航天大学辽宁省通用航空重点实验室,辽宁沈阳 110136【正文语种】中文【中图分类】V211.44某型电动飞机采用螺旋桨产生拉力,为了提高电动飞机的航时,螺旋桨必须具有较高的效率,足够的拉力,并且保证螺旋桨需用功率与电动机功率相匹配。
很多学者在高效率螺旋桨设计和分析方面开展了大量的研究。
广东医科大学2020年第一学期《医学文献检索》期末考试试卷
广东医科大学2020年第一学期《医学文献检索》期末考试试卷（适用于2019级本科护理专业）您的姓名： [填空题] *_________________________________学号： [填空题] *_________________________________一、单项选择题（共40小题，每小题1分，共40分）1、下列能够检索图书信息的数据库是（） [单选题] *A. 维普《中文科技期刊数据库》B. 万方数据资源系统C. 人大复印报刊资料全文数据库D. 超星数字图书馆(正确答案)2 、下列选项中属于特种文献类型的有（） [单选题] *A. 报纸B. 图书C. 科技期刊D. 标准文献(正确答案)3 、以刊载新闻和评论为主的文献是（） [单选题] *A. 图书B. 报纸(正确答案)C. 期刊D. 会议文献4 、在PUBMED数据库中不能对检索结果按以下哪项排序?（） [单选题] *A. Recently AddedB. First AuthorC. Time Cited(正确答案)D. Last Author5 、Web of Science的默认检索页面，提供检索的字段不包括（） [单选题] *A. Topic（主题）B. Author（作者）C. Corresponding author （通讯作者）(正确答案)D. Title（题名）6 、关于中国期刊全文数据库的“知网节”链接功能，以下说法正确的是（） [单选题] *A. “知网节”链接就是关键词链接B. “知网节”链接功能包括主题词、分类号、关键词、作者、机构以及相关文献的链接(正确答案)C. “知网节”中相关文献链接是参考文献链接D. “知网节”中相关文献链接是引证文献链接7 、常用的检索系统有（） [单选题] *A. 目录检索系统B. 文摘检索系统C. 全文检索系统D. 其余都是(正确答案)8 、下列可检索国外学位论文的数据库是（） [单选题] *A. SDOSB. KluwerC. Springer LinkD. ProQuest(PQDD)(正确答案)9 、以下哪个不属于MeSH表提供的限定词（） [单选题] *A. epidemiologyB. drug therapyC. cells(正确答案)D. utilization10 、WWW检索工具，主要检索WWW站点上的资源，通常称为搜索引擎，常用的搜索引擎有很多，下列哪个不是搜索引擎的网址（） [单选题] *A. B. C. D. (正确答案)11 、IPC是下列哪一种的缩写（） [单选题] *A. 中国专利索引B. 国际专利分类表(正确答案)C. 美国专利分类法D. 国际标准化组织12 、布尔逻辑算符通常的运算顺序是:（） [单选题] *A. 有括号时，括号内的先执行;无括号时 NOT > AND > OR(正确答案)B. 有括号时，括号内的先执行;无括号时 NOT > OR >ANDC. 有括号时，括号内的先执行;无括号时 AND >NOT > ORD. 有括号时，括号内的先执行;无括号时 AND > OR > NOT13 、哪个途径是从文献的内部特征进行检索的（） [单选题] *A. 分类途径(正确答案)B. 号码途径C. 作者途径D. 刊名途径14 、专利制度的核心是（） [单选题] *A. 专利法(正确答案)B. 新颖性C. 创造性D. 实用性15 、在PUBMED数据库中检索2003到2011年出版的文献可以用哪个检索式?（） [单选题] *A. 2003: 2011 [dp](正确答案)B. 2003-2011 [dp]C. 2003: 2011 [pd]D. 2003: 2011 [py]16 、逻辑算符包括（）算符。
操稳特性快速评估及其在飞机设计中的应用
操稳特性快速评估及其在飞机设计中的应⽤南京航空航天⼤学硕⼠学位论⽂操稳特性快速评估及其在飞机设计中的应⽤姓名：张帅申请学位级别：硕⼠专业：飞⾏器设计指导教师：余雄庆20081201南京航空航天⼤学硕⼠学位论⽂摘要飞机总体设计阶段需要对飞机设计⽅案的操稳特性作出快速评估。
在采⽤主动控制技术进⾏飞机总体设计时，还需要考虑飞⾏控制系统的作⽤，对包括飞控系统在内的全机操稳特性进⾏快速评估。
针对以上需求，本⽂主要完成了以下研究⼯作：1）对应⽤飞机操稳分析程序（DATCOM）计算⽓动系数和导数的⽅法进⾏了研究，提出了⼀些实⽤的输⼊⽂件建模⽅法，为DATCOM程序开发了输⼊与输出接⼝程序，提⾼了DATCOM 程序的使⽤效率，⽅便了程序与其它分析系统的集成。
2）应⽤Simulink对⽓动数据进⾏插值处理，并建⽴了⾮线性模型；应⽤MATLAB的功能函数实现了⾃动提取线性模型以及根据线性模型分析飞机本体的操稳特性。
3）利⽤ Simulink 的建模及仿真功能，实现了飞控系统的建模、控制律设计和仿真，并建⽴了全机仿真分析模型，实现了全机仿真模型的快速配置以及飞⾏仿真。
4）对MATLAB的RTW⼯具以及引擎技术进⾏了研究，实现了仿真模型的编译处理以及外部调⽤。
在此基础上，将带仿真模型的分析程序进⾏了编译处理；采⽤iSIGHT软件对编译⽣成的可执⾏⽂件进⾏了集成，完成了操稳特性快速评估系统的构建；系统可以单独运⾏，也可以在飞机多学科优化设计系统中作为⼦系统应⽤。
5）在飞机总体设计中应⽤操稳特性快速评估系统，研究了飞翼布局⽆⼈机的操稳特性，以及⼤型民⽤飞机放宽静稳定度技术。
应⽤研究充分表明，本⽂所提出的⽅法和建⽴的操稳特性快速评估系统特别适合飞机总体设计阶段对操稳特性的评估，为飞机多学科优化设计以及应⽤主动控制技术进⾏飞机总体设计提供了有效的操稳分析⽅法和⼯具。
关键词：飞机总体设计；操稳特性；主动控制技术；飞⾏控制系统；控制律；飞⾏仿真操稳特性快速评估及其在飞机设计中的应⽤AbstractIn the conceptual design of aircraft, the S&C (stability and control) of the aircraft need to be evaluated rapidly. When ACT (Active Control Technology) is used in the conceptual design，the rapid evaluation of the S&C need to include the FCS (Flight Control System). The Methods and tool were developed in this thesis to meet this need. The research work in this thesis is presented as the followings:1) In terms of computing aerodynamic coefficient and derivative, some useful methods for input file modeling was improved for DATCOM, some interface code for input and output of DATCOM was developed. The interface code make the DATCOM easier to use and more convenient to be integrated with other codes.2) In Simulink software environment, aerodynamic data interpolation has been completed and non-linear aerodynamic model was set up. Linear model could be extracted from non-linear model by functions in MATLAB. And then the inherent S&C of the aircraft could be analyzed.3) By use of modeling and simulation function in Simulink software, the modeling, control law designing and simulation of the FCS was completed. Then the flight simulation model of the whole aircraft with FCS could be set up.4) By use of the RTW tools and ENGINE technolony in MATLAB, flight simulation model could be compiled. Therefore, all ofthe analysis codes have been compiled to executable files. These files have been integrated by iSIGHT software and built into an integrated rapid evaluation system of the S&C. This system could be used alone or as a sub-system in MDO (Multidisciplinary Design Optimization).5) The rapid evaluation system have been verified by two examples. An unmanned air vehicle with fly-wing configuration was analyzed by this system, and a civil jet transport with RSS (Relaxed Static Stability) technolony was analyzed by this system.The applications demonstrate that the methods and rapid evaluation system developed in this thesis can meet the need of S&C evaluation in the conceptual design. It can be used as an effective tool in the conceptual design of aircraft with ACT technology, as well as a subsystem of MDO.Keywords:Conceptual Design of Aircraft; S&C; ACT; FCS; Control Law; Flight Simulation南京航空航天⼤学硕⼠学位论⽂图表清单图1.1 主动控制技术（下）与传统飞机设计⽅法（上）⽐较 (3)图1.2 飞机多学科优化设计系统框架 (4)图1.3 操稳特性快速评估系统框图 (8)图2.1 本⽂所采⽤的飞机坐标系 (9)图2.2 DATCOM输⼊⽂件的构成⽅式 (12)图2.3 DATCOM输⼊⽂件⽰例 (13)图2.4 导⼊到MATLAB中的DATCOM输出数据 (15)图2.5 输⼊接⼝程序⽣成的DATCOM输⼊⽂件及构成关系 (17)图2.6 利⽤插值处理模块对阻⼒系数有关数据插值处理 (23)图2.7 以Simulink封装模块建⽴的飞机本体⾮线性模型 (27)图2.8 以封装模块与S-function运动⽅程建⽴的飞机本体⾮线性模型 (27)图3.1 飞控系统的⼀般构成 (34)图3.2 飞机纵向线性系统仿真分析模型⽰例 (35)图3.3 ⼤⽓扰动仿真模型 (36)图3.4 爬升指令仿真模型 (37)图3.5 传感器与测量模型 (38)图3.6 ⼤⽓数据计算机仿真模型中的离散采样环节 (39)图3.7 陀螺仪和线加速度计模型 (39)图3.8 舵机仿真模型 (40)图3.9 飞机系统仿真模型 (40)图3.10 全机飞⾏仿真分析模型 (41)图3.11 Simulink与FlightGear视景仿真的接⼝模型 (43)图4.1 系统集成⽅案原理框图 (45)图4.2 采⽤iSIGHT完成的系统集成 (47)图5.1 飞翼⽆⼈机外形及舵⾯布置⽰意图 (48)图5.2 飞控系统的Simulink仿真模型 (49)图5.3 增稳后的扰动运动模态曲线（纵向） (50)图5.4 飞⾏⾼度变化仿真曲线 (50)图5.5 飞机俯仰⾓变化仿真曲线 (51)图5.6 放宽静稳定度对超声速运输机构型的影响 (52)图5.7 飞机优化设计前的基本构型 (53)操稳特性快速评估及其在飞机设计中的应⽤图5.8 优化后的平尾平⾯形状与初始设计形状的对⽐ (55)表2.1 DATCOM中常⽤参数表及控制参数的功能 (11)表2.2 常⽤的DATCOM计算输出结果 (14)表2.3 DATCOM+输出⽂件的类型及其功能 (16)表2.4 DATCOM+中各程序的功能 (16)表3.1 常⽤飞控系统的复杂度分类 (34)表3.2 FlightGear中常⽤的配置参数 (42)表4.1 操稳特性快速评估系统中的各部分程序 (44)表4.2 MATLAB引擎与VC的接⼝函数 (46)表5.1 ⽆⼈机本体扰动运动模态（纵向） (48)表5.2 增稳后的全机扰动运动模态（纵向） (49)表5.3 飞机主要的总体设计参数 (53)表5.4 设计变量、约束、⽬标及其优化结果 (54)表5.5 优化后主要外形特征参数及升阻特性的变化 (55)南京航空航天⼤学硕⼠学位论⽂注释表A展弦⽐ H , h ⾼度 a声速；主轴⽅位⾓ I 转动惯量 b展长 K n 纵向静稳定裕度 c A平均⽓动弦长 L M N 总⼒矩在机体轴系上的分量 A C轴向⼒系数 A A A L M N ⽓动⼒矩在机体轴系上的分量D C阻⼒系数 M a 飞⾏马赫数 L C升⼒系数 P 发动机推⼒或拉⼒ m C俯仰⼒矩系数 Q 动压，0.5ρV 2 N C法向⼒系数 p q r 滚转，俯仰，偏航⾓速度 L C α升⼒系数对攻⾓的导数 T 发动机作⽤⼒在机体x 轴的分量m C α俯仰静稳定性导数 u v w 空速在机体轴上的分量 Y C β侧⼒系数对侧滑⾓的导数 V 空速 n C β偏航静稳定性导数 W 飞机重量 l C β滚转静稳定性导数 cp x 压⼒中⼼的相对位置 Lq C升⼒系数对俯仰⾓速度的导数 ac x 焦点（⽓动中⼼）的相对位置mq C 俯仰⼒矩系数对俯仰⾓速度的导数cg x 重⼼的相对位置L C α升⼒系数对攻⾓变化率的导数 Y 侧⼒ m C α俯仰⼒矩系数对攻⾓变化率的导数α攻⾓（迎⾓） Yp C侧⼒系数对滚转⾓速度的导数β铡滑⾓ lp C滚转阻尼导数 e δ升降舵偏转⾓ lr C滚转交叉导数 f δ襟翼偏转⾓ np C航向交叉导数 a δ副翼偏转⾓ nr C航向阻尼导数φ滚转⾓ C P螺旋桨拉⼒系数θ俯仰⾓ D阻⼒ψ偏航⾓ F x F y F z空⽓动⼒在机体轴系上的分⼒ρ空⽓密度 G重⼒ξ阻尼⽐ g重⼒加速度 n ω固有频率承诺书本⼈声明所呈交的硕⼠学位论⽂是本⼈在导师指导下进⾏的研究⼯作及取得的研究成果。
空气动力学学报说明书
空气动力学学报(双月刊)第35卷 第6期(总第167期)(K O N G Q I D O N G L I X U EX U EB A O )2017年12月目 次综述现代大型飞机起落架气动噪声研究进展刘沛清,邢 宇,李 玲,郭 昊 (751)…………………………………………………研究论文基于P O D 方法的复杂外形飞行器热环境快速预测方法聂春生,黄建栋,王 迅,李 宇 (760)………………………………高超声速风洞轴对称喷管收缩段设计胡振震,李震乾,陈爱国,石义雷 (766)……………………………………………………高超声速壁湍流入口条件生成方法的比较禹 旻,袁湘江,朱志斌 (772)………………………………………………………尖楔前体飞行器F A D S 系统的神经网络算法王 鹏,胡远思,金 鑫,张卫民 (777)……………………………………………翼吊布局民机短舱位置气动影响张冬云,张美红,王美黎,向传涛 (781)…………………………………………………………一种仿H X 扁平面对称类升力体布局气动特性分析刘深深,解 静,冯 毅,唐 伟,桂业伟 (787)…………………………过失速薄翼增升流动控制方法吴继飞,王志金,G U R S U LI s m e t (792)……………………………………………………………电大尺寸目标电磁散射的并行F V T D 计算许 勇,黄 勇,余永刚 (797)………………………………………………………城市地貌高空台风特性及湍流积分尺度的研究王澈泉,李正农,胡佳星,张学文,周利芬,曹守坤 (801)……………………基于网格框架的结构网格自动重构技术庞宇飞,卢风顺,蔡云龙,张书俊,孙俊峰 (807)………………………………………基于P a r e t o 分布的风压极值计算方法李正农,曹守坤,王澈泉 (812)……………………………………………………………荧光油流显示技术在高超声速风洞中的应用陈 磊,朱 涛,徐 筠,江 涛 (817)……………………………………………民用飞机静压孔布局规律周 峰,赵克良,张 淼,汪君红 (823)…………………………………………………………………电弧风洞转动部件动密封试验杨远剑,陈德江,赵文峰,张松贺,江 波 (828)…………………………………………………飞翼布局气动外形设计余永刚,黄 勇,周 铸,黄江涛 (832)……………………………………………………………………导弹侧向喷流干扰及多喷口耦合效应数值模拟贾洪印,吴晓军,周乃春,赵 辉 (837)…………………………………………大展弦比机翼跨声速静气动弹性风洞试验郭洪涛,陈德华,吕彬彬,余 立,祖孝勇 (841)……………………………………考虑隐身约束的舰载飞翼无人机翼尖装置气动设计和分析李继广,陈 欣,李 震 (846)……………………………………飞翼布局飞行器舵面缝隙对操纵效率的影响姚军锴,曹德一,何海波 (850)……………………………………………………移动式冰风洞试验方法研究和应用李 斯,于 雷,金 沙,裴如男 (855)………………………………………………………空气动力分析中动网格技术的数值阻尼赵张峰,邓洪洲 (860)……………………………………………………………………渐扩后倾肩臂孔平板气膜冷却特性数值模拟黄 康,马护生 (866)………………………………………………………………低速高雷诺数风洞腹撑支架干扰研究郑新军,焦仁山,苏文华,马洪雷,张连河 (870)…………………………………………8mˑ6m 风洞大尺度模型进气道和喷流试验技术陈 洪,刘李涛,巫朝君 (875)………………………………………………扇翼飞行器气动特性优化设计李仁凤,乐贵高,马大为,陈 帅 (879)……………………………………………………………偏转头弹箭飞行特性张志勇,陈志华,黄振贵 (883)………………………………………………………………………………分离形式后体喷流试验技术及阻力修正方法邓祥东,郭大鹏,季 军,白玉平,杨庆华 (887)…………………………………基于自适应重叠网格的三角翼跨声速流场计算王 娜,叶 靓 (893)……………………………………………………………低亚声速火箭橇尾流场特性分析房 明,孙建红,王从磊,余元元,张延泰 (897)………………………………………英文编审: 姜 屹 责任编辑: 王 颖期刊基本参数:C N 51-1192/T K*1980*q *16*168*z h +e n *P *￥30.00*1000*30*2017-12A C T A A E R O D Y N A M I C A S I N I C AC h i n e s eA e r o d y n a m i c sR e s e a r c hS o c i e t yV o l .35,N o .6, D e c .,2017C O N T E N T S R e v i e wP r o g r e s s i na e r o a c o u s t i c i n v e s t i g a t i o no fm o d e r n l a r g e a i r c r a f t l a n d i n gge a r L I UP e i q i n g ,X I N G Y u ,L IL i n g ,G U O H a o (751)……R e s e a r c hA r t i c l e sF a s t a e r o h e a t i n gp r e d i c t i o nm e t h o d f o r c o m p l e x s h a p e v e h i c l e sb a s e do n p r o p e r o r t h o g o n a l d e c o m po s i t i o n ……………… N I EC h u n s h e n g ,HU A N GJ i a n d o n g,WA N G X u n ,L IY u (760)……………………………………………………………………C o n t r a c t i o nd e s i g n f o r a x i s -s y mm e t r i cn o z z l e s i nh y p e r s o n i cw i n d t u n n e l …………………………………………………… HUZ h e n z h e n ,L I Z h e n q i a n ,C H E N A i g u o ,S H IY i l e i (766)…………………………………………………………………………A s s e s s m e n t o f i n f l o wb o u n d a r y c o n d i t i o n s f o r h y pe r s o n i cw a l l b o u n d e d t u r b u l e n tf l o w s …………………………………… Y U M i n ,Y U A N X i a ng j i a n g,Z HUZ h i b i n (772)……………………………………………………………………………………N e u r a l n e t w o r ka l g o r i t h mf o rF A D Ss y s t e ma p p l i e d t o t h e v e h i c l e sw i t hs h a r p w e d g e d f o r e -b o d i e s ……………………… WA N GP e n g,HU Y u a n s i ,J I N X i n ,Z HA N G W e i m i n (777)………………………………………………………………………A e r o d y n a m i c i n f l u e n c e o f n a c e l l e p o s i t i o no f aw i n g -m o u n t e d c i v i l a i r c r a f t …………………………………………………… Z H A N G D o n g y u n ,Z H A N G M e i h o n g,WA N G M e i l i ,X I A N GC h u a n t a o (781)………………………………………………………A e r o d y n a m i c c h a r a c t e r i s t i c s a n a l y s i s f o rH Xa n a l o g l i f t i n g b o d y……………………………………………………………… L I US h e n s h e n ,X I EJ i n g,F E N G Y i ,T A N G W e i ,G U IY e w e i (787)………………………………………………………………L i f t e n h a n c e m e n t c o n t r o lm e t h o do f t h i n f l a t -p l a t e a t p o s t s t a l l a n g l e s o f a t t a c k …………………………………………… WUJ i f e i ,WA N GZ h i j i n ,G U R S U LI s m e t (792)……………………………………………………………………………………P a r e l l e l F V T Dc o m p u t a t i o n f o r e l e c t r o m a g n e t i c s c a t t e r i n g o f e l e c t r i c a l l y l a r g e o b je c t s …………………………………… X U Y o n g ,HU A N G Y o n g ,Y U Y o n g g a n g(797)……………………………………………………………………………………S t u d y o n t y p h o o n c h a r a c t e r i s t i c s a t h i g hu r b a n l a n d f o r ma l t i t u d e a n d t u r b u l e n c e i n t e g r a l l e n gt hs c a l e …………………… WA N GC h e q u a n ,L I Z h e n g n o n g ,HUJ i a x i n g,Z HA N G X u e w e n ,Z H O U L i f e n ,C A Os h o u k u n (801)………………………………A u t o m a t i c r e m e s h i n g t e c h n i qu e f o r s t r u c t u r e d g r i db a s e do n g r i d f r a m e w o r k ……………………………………………… P A N G Y u f e i ,L U F e n g s h u n ,C A IY u n l o n g ,Z H A N GS h u j u n ,S U NJ u n f e n g(807)…………………………………………………M e t h o do f e s t i m a t i n g ex t r e m ew i n d p r e s s u r eb a s e do n t h eP a r e t od i s t r i b u t i o n ……………………………………………… L I Z h e n g n o n g ,C A OS h o u k u n ,W a n g C h e qu a n (812)………………………………………………………………………………A p p l i c a t i o n s o f f l u o r e s c e n c e -o i l -f l o wv i s u a l i z a t i o n t e c h n i q u e i nh y p e r s o n i cw i n d t u n n e l t e s t ……………………………… C H E NL e i ,Z HU T a o ,X U Y u n ,J I A N G T a o(817)…………………………………………………………………………………S t a t i c p o r t o r i e n t a t i o n r u l e f o r c i v i l a i r c r a f t Z HO U F e n g ,Z HA O K e l i a n g ,Z H A N G M i a o ,WA N GJ u n h o n g(823)……………………S e a l c o m pl e m e n t a t i o n t e s t f o r r o t a t a b l e p a r t s i na r ch e a t e dw i n d t u n n e l ……………………………………………………… Y A N G Y u a n j i a n ,C H E N D e j i a n g ,Z H A O W e n f e n g ,Z H A N GS o n gh e ,J I A N GB o (828)……………………………………………A e r o d y n a m i c d e s i g no f a f l y i n g -w i n g a i r c r a f t Y U Y o n g g a n g ,HU A N G Y o n g ,Z H O UZ h u ,HU A N GJ i a n g t a o (832)…………………N u m e r i c a l i n v e s t i g a t i o no n c o u p l i n g e f f e c t s o fm u l t i p l e s p o u t s a n d l a t e r a l j e t i n t e r a c t i o no v e rm i s s i l e c o n f i gu r a t i o n …… J I A H o n g y i n ,WU X i a o ju n ,Z HO U N a i c h u n ,Z H A O H u i (837)……………………………………………………………………W i n d t u n n e l t e s t o n t r a n s o n i c s t a t i c a r e o e l a s t i c i t y o f h i g h -a s p e c t -r a t i ow i n g ………………………………………………… G U O H o n g t a o ,C H E N D e h u a ,L Y U B i n b i n ,Y U L i ,Z U X i a o y o n g (841)……………………………………………………………A e r o d y n a m i c d e s i g na n da n a l y s i s o f t i p d e v i c e s o n c a r r i e r -b a s e d f l y -w i n g U A V w i t hs t e a l t hc o n s t r a i n t s ………………… L I J i gu a n ,C H E N X i n ,L I Z h e n (846)………………………………………………………………………………………………G a p i n f l u e n c e o n r u d d e r e f f i c i e n c y o f f l y i n g w i n g ai r c r a f t Y A OJ u n k a i ,C A O D e y i ,H E H a i b o (850)………………………………S t u d y a n da p p l i c a t i o no fm o v a b l e i c i n g wi n d t u n n e l t e s tm e t h o d L I S i ,Y U L e i ,J I NS h a ,P E IR u n a n (855)………………………N u m e r i c a l d a m p i n g o f d y n a m i cm e s h f o r a e r o d y n a m i c a n a l ys i s Z HA OZ h a n g f e n g ,D E N G H o n g z h o u (860)…………………………N u m e r i c a l s i m u l a t i o no n c o o l i n g c h a r a c t e r i s t i c s o f p l a t e f i l mf r o mb a c k w a r d -e x p a n d i n g s h o u l d e r a r mh o l e ……………… HU A N G K a n g ,MA H u s h e n g (866)…………………………………………………………………………………………………V e n t r a l s u p p o r t i n t e r f e r e n c e i n l o w -s p e e da n dh i g hR e y n o l d sn u m b e rw i n d t u n n e l ………………………………………… Z H E N G X i n j u n ,J I A O R e n s h a n ,S U W e n h u a ,MA H o n g l e i ,Z H A N GL i a n h e (870)…………………………………………………I n l e t a n d j e t t e s t t e c h n i q u e s f o r l a r g e s c a l em o d e l i n8mˑ6m L o wS pe e d W i n dT u n n e l …………………………………… C H E N H o n g ,L I U L i t a o ,WU C h a o ju n (875)………………………………………………………………………………………O p t i m i z a t i o nd e s i g n f o r a e r o d y n a m i c p e r f o r m a n c e o f f a n -w i n g a i r c r a f t L IR e n f e n g ,L EG u i g a o ,MA D a w e i ,C H E NS h u a i (879)…F l i g h t c h a r a c t e r i s t i c s o f d e f l e c t e dn o s e p r o je c t i l e Z H A N GZ h i y o n g ,C H E NZ h i h u a ,HU A N GZ h e n g u i (883)…………………………S l e e v e -t y p e af t e r b o d y j e t e x p e r i m e n t t e c h n i q u e a n d i t s d r ag c o r r e c t i o nm e th o d ……………………………………………… D E N G Xi a n g d o n g ,G U O D a p e n g ,J I J u n ,B A IY u p i n g ,Y A N G Q i n g h u a (887)………………………………………………………N u m e r i c a l s i m u l a t i o no f t r a n s o n i c f l o wf i e l do v e r d e l t aw i n g w i t ha d a p t i v e o v e r l a p p e d g r i d s ys t e m ……………………… WA N G N a ,Y EL i a n g(893)…………………………………………………………………………………………………………A n a l ys i s o fw a k e f l o wc h a r a c t e r i s t i c s f o r l o ws u b s o n i c r o c k e t s l e d …………………………………………………………… F A N G M i n g ,S U NJ i a n h o n g ,WA N GC o n g l e i ,Y U Y u a n y u a n ,Z h a n g Ya n t a i (897)…………………………………………………现代大型飞机起落架气动噪声研究进展(751-759,d o i:10.7638/k q d l x x b-2017.0063)刘沛清,邢宇,李玲,郭昊主要概括了国内外在大型飞机起落架气动噪声研究领域,利用风洞试验㊁飞行试验和数值模拟等手段,所取得的研究成果和最新进展㊂主要包括起落架噪声的产生机理㊁起落架降噪的主要方法㊁风洞试验需要遵循的相似律和工程预测起落架噪声方法的发展等㊂并对起落架噪声的未来研究进行了展望㊂基于P O D方法的复杂外形飞行器热环境快速预测方法(760-765,d o i:10.7638/k q d l x x b-2015.0157)聂春生,黄建栋,王迅,李宇采用本征正交分解对数据库进行降阶处理,结合相应的基系数插值方法,快速预测出未知状态热流㊂与C F D结果的对比表明,该方法可大幅提高计算效率且不损失预测精度,实现了沿给定弹道的三维热环境快速预测,能够反映真实的热流空间分布特征,快速获得激波干扰区热流,有力地弥补了工程算法的不足㊂高超声速风洞轴对称喷管收缩段设计(766-771,d o i:10.7638/k q d l x x b-2015.0141)胡振震,李震乾,陈爱国,石义雷构造了A Q A曲线,分析了高超声速风洞轴对称喷管喉道曲率半径是否连续对喉部流动和喷管出口流场的影响㊂研究结果表明喉道曲率半径连续时结果达到最佳,而上游曲率半径偏大优于偏小的情况㊂基于三角/双曲函数设计了一种新的收缩曲线,与B样条函数构造的曲线一样可达到出入口曲率半径任意可调的目的,但控制更为方便,是确保喉道曲率连续的不错选择㊂高超声速壁湍流入口条件生成方法的比较(772-776,d o i:10.7638/k q d l x x b-2015.0177)禹旻,袁湘江,朱志斌给定恰当的入口条件是开展壁湍流数值模拟的关键问题㊂采用直接数值模拟,讨论了自然转捩㊁波纹壁面促发的"B y p a s s"转捩和利用时间发展湍流场进行参数回收这几种方法在高超声速条件下的可行性,分析了各自存在的优点和不足㊂计算表明,B y p a s s转捩和参数回收方法与自然转捩相比,能更快速促发转捩,但自然转捩得到的湍流场品质更好㊂尖楔前体飞行器F A D S系统的神经网络算法(777-780,791,d o i:10.7638/k q d l x x b-2015.0064)王鹏,胡远思,金鑫,张卫民对人工神经网络算法在尖楔前体飞行器用嵌入式大气数据传感系统中的应用进行了探讨㊂通过合理选择网络结构参数及训练验证,分别建立了F A D S系统的含有单隐含层的三层神经网络模型及含有双隐含层的四层神经网络模型,对攻角等飞行参数参数进行求解㊂数值仿真结果表明,建立的用于尖楔前体飞行器的F A D S系统的神经网络算法求解精度较高,且含有双隐含层的网络模型精度优于单隐含层的模型精度㊂Ⅰ文章导读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍翼吊布局民机短舱位置气动影响(781-786,d o i :10.7638/k q d l x x b -2015.0069)张冬云,张美红,王美黎,向传涛使用C F D 方法对孤立通气短舱㊁某型民机机翼/机身组合体以及机翼/机身/短舱组合体构型进行粘性绕流数值模拟,分析流场特征,得出短舱安装干扰阻力水平;分别改变短舱安装的前伸量㊁下沉量㊁俯仰角㊁内撇角等参数,研究短舱不同在翼位置对高速巡航升阻特性的影响㊂一种仿H X 扁平面对称类升力体布局气动特性分析(787-791,d o i :10.7638/k q d l x x b -2015.0187)刘深深,解静,冯毅,唐伟,桂业伟提出了一种对H T V -2进行改进的仿H X 气动模型,对二者气动特性进行了对比分析㊂探究了仿H X 外形的横侧向稳定性,对两侧小翼关键气动布局参数进行了分析,对控制舵进行了匹配设计㊂结果表明H X 外形能够增强偏航稳定性,其效果与翼高及面积呈正相关,小安装角度下对安装角度不敏感㊂经过匹配设计,该方案具备较高的控制效率和合理的配平攻角范围㊂过失速薄翼增升流动控制方法(792-796,d o i :10.7638/k q d l x x b -2015.0068)吴继飞,王志金,G U R S U LI s m e t采用吸气流动控制方法对薄翼升力特性进行了试验研究,来流速度为5m /s ,雷诺数R e =6.7ˑ104㊂研究表明,过失速条件下,合适的吸气控制可以使翼型失速迎角延迟近7ʎ,最大升力系数可增大近一倍;在翼型前缘进行吸气流动控制时,较小吸气流量即可延缓翼型失速;流动控制参数存在优化空间,当吸气相对位置位于x /c =0.4附近时,吸气流量小于3%即可产生较大的升力增量㊂电大尺寸目标电磁散射的并行F V T D 计算(797-800,d o i :10.7638/k qd l x x b -2015.0071)许勇,黄勇,余永刚电大尺寸目标电磁问题的高精度数值计算通常伴随着大存储量和大计算量的沉重负担㊂本文构建了直接求解电磁学麦克斯韦方程组的时域有限体积法(F V T D )解算器,解决大规模网格的大计算量,采用M P I 并行编程,进行网格分割㊁负载平衡以及通信设置,对电大尺寸飞翼外形进行了L 波段双站电磁散射计算㊂结果表明p m b R C S 3d 这一并行高精度电磁模拟软件具有稳定和鲁棒特性,适合应用于目标更高频段电磁计算㊂城市地貌高空台风特性及湍流积分尺度的研究(801-806,822,d o i :10.7638/k q d l x x b -2015.0090)王澈泉,李正农,胡佳星,张学文,周利芬,曹守坤基于2014年第10号台风麦德姆 在城市地貌的高空实测风场资料,共选取五个时距分析其特性㊂然后采用两种基于T a y l o r 假定的方法来计算湍流积分尺度,分别从平均风速㊁湍流度和阵风因子等要素来探讨不同时距对湍流积分尺度的影响㊂分析结果表明当平均时距为5m i n 时最为合理㊂Ⅱ文 章 导 读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍基于网格框架的结构网格自动重构技术(807-811,d o i:10.7638/k q d l x x b-2015.0179)庞宇飞,卢风顺,蔡云龙,张书俊,孙俊峰针对多学科耦合计算过程中出现的外形剧烈变化情况,提出了一种基于网格框架的多块结构网格自动重构技术,基本思想是:首先提取多块分区结构网格的网格框架,然后借助其它学科计算得到的物面变形信息以及拟合样条曲线来重构框架线,最后利用更新的框架线自动生成变形网格㊂该方法已被应用到某翼身组合体外形的气动弹性计算㊂基于P a r e t o分布的风压极值计算方法(812-816,d o i:10.7638/k q d l x x b-2015.0143)李正农,曹守坤,王澈泉通过P a r e t o分布I型分布拟合峰值样本的高尾部数据,利用广义极值分布和广义P a r e t o分布之间的关系对风压的极值做出估计,得到基于P a r e t o分布的风压极值计算方法㊂利用高层建筑风洞试验多次独立采样得到的数据,将基于P a r e t o分布的风压极值计算方法从风压极值的期望值和指定保证率的极值两个方面进行了验证㊂荧光油流显示技术在高超声速风洞中的应用(817-822,d o i:10.7638/k q d l x x b-2015.0150)陈磊,朱涛,徐筠,江涛通过原理性试验分析了系统组成中主要部件的参数指标,搭建了试验平台,完成不同颜色和类型荧光示踪剂的对比试验,筛选出性能可靠的荧光示踪剂,制作了荧光油膜,最后成功地将荧光油流技术应用到C A R D C 中的Φ1m高超声速风洞中㊂该技术具有信噪比高㊁精度高㊁获取到信息的细节量多等优点㊂最后对荧光油流图像定量化显示技术进行了研究,结果表明,根据荧光油膜发出的荧光信号,能够推算出荧光油膜的厚度信息㊂民用飞机静压孔布局规律(823-827,d o i:10.7638/k q d l x x b-2015.0140)周峰,赵克良,张淼,汪君红对民用飞机静压孔布局规律进行了研究㊂利用数值模拟方法得到机身表面静压随马赫数㊁攻角变化较小的区域,定义为稳压线;通过圆柱绕流压力分布理论,获得与数值模拟结果一致的稳压线分布规律㊂开展高/低速测压风洞试验,结果表明稳压线及静压孔布局规律的正确㊁普适㊂所得稳压线分布规律可为常规布局民用飞机静压孔布局提供直接参考㊂电弧风洞转动部件动密封试验(828-831,d o i:10.7638/k q d l x x b-2015.0147)杨远剑,陈德江,赵文峰,张松贺,江波翼/舵等部件在转动条件下热结构/匹配/密封考核一直是高超声速飞行器研制阶段的技术难点㊂为此在电弧风洞上开展了相应的试验技术研究,针对关键技术问题提出了解决方案㊂试验结果表明:试验模型表面热流分布与飞行条件下较为一致,转动过程中流场稳定,在国内首次实现了高超声速飞行器转动部件动密封地面试验考核㊂Ⅲ文章导读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍飞翼布局气动外形设计(832-836,878,d o i :10.7638/k q d l x x b -2015.0163)余永刚,黄勇,周铸,黄江涛双后掠前缘飞翼布局的纵向气动特性设计主要难点是如何在小俯仰力矩的约束下实现高升阻比设计㊂本文从平面形状㊁重心位置㊁翼型选择/优化与配置等方面提出了一些设计思路,并以此设计了气动外形㊂通过数值模拟和风洞试验两种手段,验证了设计思路的合理性㊂该布局在亚声速设计点具有较高升阻比和较小的俯仰力矩系数㊂导弹侧向喷流干扰及多喷口耦合效应数值模拟(837-840,d o i :10.7638/k q d l x x b -2015.0083)贾洪印,吴晓军,周乃春,赵辉利用数值模拟手段对导弹的侧向喷流干扰流场进行了研究,重点讨论了采用空气冷喷流模拟的相似准则问题㊂通过与燃气喷流的对比,验证了方法的可靠性㊂对某导弹外形的多喷口耦合效应进行了研究,分析了侧向多喷口耦合干扰下的放大因子及流场结构,相关结论可为导弹喷流控制系统设计提供参考依据㊂大展弦比机翼跨声速静气动弹性风洞试验(841-845,d o i :10.7638/k q d l x x b -2015.0075)郭洪涛,陈德华,吕彬彬,余立,祖孝勇基于风洞试验研究了某翼身组合体的跨声速静气动弹性效应㊂研究结果表明:在设计巡航点,静气动弹性可使机翼的升力系数减小㊁升阻比增加㊁焦点前移,并在超过巡航马赫数后使得气动特性恶化㊂试验结果表明,跨声速时,马赫数和速压对静气动弹性效应具有较大影响,且影响规律呈复杂非线性特征,难以仅靠理论分析准确预计㊂考虑隐身约束的舰载飞翼无人机翼尖装置气动设计和分析(846-849,d o i :10.7638/k q d l x x b -2015.0061)李继广,陈欣,李震在隐身要求约束下,设计了舰载飞翼无人机翼下增升装置㊂并针对未来雷达探测的反隐身技术,分析了增升装置对尾流消弱的作用,从而提高了该探测方式的隐身效果㊂计算结果表明,该增升装置可以较好地增加升力㊁减弱诱导阻力㊁提高升阻比,并能起到减弱尾流的作用㊂最后分析了其机理,解释了大迎角条件下气动优化效果更好的原因,并与常规布局飞机翼尖小翼的作用作了对比㊂飞翼布局飞行器舵面缝隙对操纵效率的影响(850-854,d o i :10.7638/k q d l x x b -2015.0088)姚军锴,曹德一,何海波采用数值模拟方法分析了飞翼布局飞行器舵面缝隙对各舵面操纵效率的影响㊂结果表明:舵面缝隙使得内侧㊁外侧升降副翼的操纵效率均有所降低;有缝隙存在时开裂式方向舵的操纵效率比无缝隙高㊂内㊁外侧升降副翼操纵效率降低的原因是下表面气流通过舵面缝隙流至上表面从而降低了上下表面压力差和阻滞了主流;开裂式方向舵大舵偏时操纵效率增加的机理在于有缝隙时下翼面高压气流通过缝隙注入上翼面回流区从而降低回流范围㊂Ⅳ文 章 导 读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍移动式冰风洞试验方法研究和应用(855-859,d o i:10.7638/k q d l x x b-2015.0121)李斯,于雷,金沙,裴如男开展了移动式冰风洞喷雾参数测量,进行了发动机短舱唇口模型㊁N A C A23012翼型模型的结冰和防/除冰试验,掌握了移动式冰风洞云雾校测㊁试验的基本方法㊂移动式冰风洞在户外模拟结冰条件虽然受环境因素影响较大,但喷雾性能良好,试验结果能够反映一般结冰规律,可以满足飞机进气系统防/除冰试验要求㊂空气动力分析中动网格技术的数值阻尼(860-865,d o i:10.7638/k q d l x x b-2015.0080)赵张峰,邓洪洲在F L U E N T中动网格宏模块由于数据传递方式的限制,修改了常加速度N e w m a r k法的原有算法,模块软件算法的有效性存在质疑㊂针对这个问题,首先给出算例来显示软件算法的缺陷特征,提出了软件算法会引入数值阻尼的假定;而后通过数学手段证明数值阻尼的存在,并给出数值阻尼的理论计算公式;之后通过算例验证理论公式的有效性;最后给出了理论的工程应用㊂渐扩后倾肩臂孔平板气膜冷却特性数值模拟(866-869,d o i:10.7638/k q d l x x b-2015.0081)黄康,马护生为进一步改善气膜冷却效果,提出了渐扩后倾肩臂孔的构型㊂对圆形孔㊁扩张孔㊁原肩臂孔和渐扩后倾肩臂孔在吹风比0.5~2.0情况下的平板气膜冷却特性进行了数值计算㊂结果表明,采用渐扩后倾肩臂孔的平板模型可提高展向平均气膜冷却效率,在各吹风比方案下气膜冷却性能均优于其它三种孔型㊂低速高雷诺数风洞腹撑支架干扰研究(870-874,d o i:10.7638/k q d l x x b-2015.0114)郑新军,焦仁山,苏文华,马洪雷,张连河针对F L-9低速高雷诺数风洞腹撑支架干扰问题,采用风洞试验研究的方法,开展了F L-9风洞内式天平腹撑支杆的二维截面形状㊁三维外形㊁支杆直径选取等相关研究㊂获得了对雷诺数不敏感㊁支架干扰量小且稳定的腹撑支杆方案,并通过与其他风洞试验结果的对比,进一步验证了F L-9风洞内式天平单支杆腹撑系统的精准度㊂8mˑ6m风洞大尺度模型进气道和喷流试验技术(875-878,d o i:10.7638/k q d l x x b-2015.0133)陈洪,刘李涛,巫朝君采用单台抽吸流量达383m3/m i n的真空泵抽吸系统和最大落压比达3.5的喷流模拟器,在8mˑ6m风洞建立了大尺度模型进气道和喷流试验技术,可实现8mˑ6m试验段大尺度战斗机100%进气流量和高落压比模拟要求,能够更为精细地模拟战斗机气动外形,获得更为准确的进气道性能㊁喷流对战斗机气动特性影响及矢量喷管性能参数㊂Ⅴ文章导读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍扇翼飞行器气动特性优化设计(879-882,892,d o i :10.7638/k q d l x x b -2015.0173)李仁凤,乐贵高,马大为,陈帅采用多目标优化和数值模拟结合的方法对扇翼飞行器气动特性进行了优化设计㊂计算得到多结构参数影响下扇翼飞行器高升力㊁低阻力的优化结构参数和主要影响因素㊂研究结果表明,建立的近似数学模型和优化结果精度较高,满足工程需要㊂优化后,扇翼飞行器的升力和推力较大,飞行器气动特性得到显著改善㊂偏转头弹箭飞行特性(883-886,d o i :10.7638/k q d l x x b -2015.0182)张志勇,陈志华,黄振贵偏转头弹箭通过头部偏转来改变气动力,达到增加弹箭射程与提高机动性的目的㊂对头部偏转角0ʎ~8ʎ㊁马赫数2~5条件下的飞行流场进行数值模拟并验证仿真的可靠性㊂然后利用仿真数据计算偏转头弹箭的外弹道轨迹,结果表明,偏转头弹箭能带迎角稳定飞行,其升阻比远大于普通弹箭,弹箭射程提高且机动性能优于普通弹箭㊂分离形式后体喷流试验技术及阻力修正方法(887-892,d o i :10.7638/k qd l x x b -2015.0113)邓祥东,郭大鹏,季军,白玉平,杨庆华详细介绍了分离形式后体喷流模型设计中需要注意的关键技术问题,以及相应的设计方法㊂针对某型飞机,精细化设计后体喷流模型的密封以及内外腔压力监测点,并对天平阻力项结果进行修正,得到与国外同类型试验阻力测量精度相一致的结果,阻力测量精度达到0.0005㊂证明该修正方法能有效地应用于分离形式后体喷流试验阻力数据的修正,精度满足国军标阻力测量指标㊂基于自适应重叠网格的三角翼跨声速流场计算(893-896,d o i :10.7638/k q d l x x b -2016.0138)王娜,叶靓在自适应重叠网格系统下,数值求解N a v i e r -S t o k e s 方程,开展了钝前缘三角翼跨声速流场的计算研究㊂网格方面采用了贴体网格与可自适应的直角网格交叠来捕捉脱体涡系的发展变化及涡与激波的干扰㊂比较了雷诺平均与D E S 计算的结果差异㊂在重叠网格系统下,网格构建简便,适用性好;对于大迎角状态,D E S 方法能够有效地模拟脱体涡系的发展变化㊂低亚声速火箭橇尾流场特性分析(897-901,d o i :10.7638/k qd l x x b -2017.0132)房明,孙建红,王从磊,余元元,张延泰采用不可压N a v i e r -S t o k e s 方程和R e a l i z a b l e k -ε湍流模型,对低亚声速条件下火箭橇试验的流场进行数值模拟,得到了火箭橇的流场特性,并与飞机流场进行了对比㊂结果表明,低亚声速情况下(60~90m /s ),火箭橇的阻力系数约为0.65,升力系数约为-0.005,并且气动升力小于自重的1.9%㊂速度对流场特性影响小,护板可改善尾流特性,与飞机尾流特性具有较好的相似性㊂Ⅵ文 章 导 读췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍第35卷 第6期空气动力学学报V o l .35,N o .62017年12月A C T AA E R O D Y N A M I C AS I N I C A D e c .,2017췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍췍文章编号:0258-1825(2017)06-0751-09现代大型飞机起落架气动噪声研究进展刘沛清*,邢 宇,李 玲,郭 昊(北京航空航天大学航空科学与工程学院,北京 100083)摘 要:起落架部件是现代大型飞机在起飞㊁着陆阶段时最主要的一类机体气动噪声源㊂本文主要概括了国内外利用风洞试验㊁飞行试验和数值模拟等手段在大型飞机起落架气动噪声研究领域所取得的研究成果和最新进展,主要包括起落架噪声的产生机理㊁起落架降噪的主要方法㊁风洞试验需要遵循的相似律和工程预测起落架噪声方法的发展等㊂已有的研究表明,起落架宽频噪声主要包括分离噪声和上下游部件相互干扰噪声两类,而纯音噪声主要来自空腔结构的声激振现象㊂使用整流罩㊁等离子体激励等主㊁被动控制技术抑制钝体分离和流动干扰现象,这些方法能够显著降低起落架噪声㊂文末还对起落架噪声的未来研究进行了展望㊂关键词:起落架;气动噪声;风洞试验;噪声机理;降噪技术中图分类号:V 226;T B 533+.3 文献标识码:A d o i :10.7638/k q d l x x b -2017.0063 收稿日期:2017-04-19; 修订日期:2017-06-13基金项目:国家自然科学基金(11772033)作者简介:刘沛清*(1960-),男,教授,博导,主要从事空气动力学㊁水动力学实验和数值模拟工作.E -m a i l :l p q@b u a a .e d u .c n 引用格式:刘沛清,邢宇,李玲,等.现代大型飞机起落架气动噪声研究进展[J ].空气动力学学报,2017,35(6):751-759.d o i :10.7638/k q d l x x b -2017.0063 L I UPQ ,X I N GY ,L I L ,e t a l .P r o g r e s s i n a e r o a c o u s t i c i n v e s t i g a t i o no fm o d e r n l a r g e a i r c r af t l a n d i n gg e a r [J ].A c t aA e r o d yn a m i c aS i n i c a ,2017,35(6):751-759.P r o g r e s s i na e r o a c o u s t i c i n v e s t i g a t i o no fm o d e r n l a r g e a i r c r a f t l a n d i n g ge a r L I U P e i q i n g *,X I N G Y u ,L IL i n g,G U O H a o (S c h o o l o f A e r o n a u t i cS c i e n c e a n dE n g i n e e r i n g ,B e i h a n g U n i v e r s i t y ,B e i j i n g 100083,C h i n a ) A b s t r a c t :L a n d i n g g e a ri so n eo ft h e m o s ti m p o r t a n ta e r o a c o u s t i cn o i s es o u r c e sd u r i n gm o d e r n l a r g ea i r c r a f t st a k e o f fa n dl a n d i n g .T h i s p a pe rs o m er e s e a r c ha c h i e v e m e n t sa n dl a t e s t d e v e l o p m e n t s m a d e t h r o u g h w i n d t u n n e l e x p e r i m e n t s ,f l y o v e r e x pe r i m e n t s a n d n u m e r i c a l s i m u l a t i o n s i n t h e a e r o a c o u s t i c i n v e s t i g a t i o nf i e l d o f l a n d i ng g e a r i n th e l a s t d e c a d e s .T hi s p a pe r a b r i ef o v e r v i e w o f f o u ra s p e c t s i n c l u d i ng th en o i s e g e n e r a t i o n m e c h a n i s m s ,t h en o i s er e d u c t i o n t e c h n i q u e s ,t h e s i m i l a r i t y r u l e o f w i n d t u n n e la e r o a c o u s t i c e x pe r i m e n t s a n d t h e p r e d i c t i o n m e t h o d sf o r l a n d i n gg e a r s .L a n d i n gg e a rb r o a d b a n dn o i s ec a nb e g e n e r a l l y c a t e g o r i z e d i n t ot w o p a r t s i s th e f l o ws e p a r a ti o n i n d u c e dn o i s e a n d t h e o t h e r i s t h e i n t e r a c t i o nn o i s e b e t w e e nu ps t r e a m a n dd o w n s t r e a m c o m p o n e n t s .M o r e o v e r ,t h er e s o n a n t p h e n o m e n o na p p e a r e di ns o m ec a v i t yc o n f i g u r a t i o n s c a na l s o g e n e r a t et o n a ln o i s e .S o m ea c t i v ea nd p a s s i v en o i s ere d u c t i o n m e t h o d s s u c ha sf a i r i ng a n d p l a s m aa c t u a t o r s whi c hc a ns u p p r e s st h ef l o w s e pa r a t i o na n di n t e r a c t i o n p h e n o m e n aa r eu s e dt or e d u c el a n d i n gg e a rn o i s e .F i n a l l y,p r e d i c t i o no ff u r t h e rr e s e a r c h o n l a n d i n gge a r n o i s e i s p r e s e n t e d . K e yw o r d s :l a n d i n gg e a r ;a e r o a c o u s t i c s ;w i n dt u n n e le x p e r i m e n t ;n o i s e g e n e r a t i o n m e c h a n i s m ;n o i s e r e d u c t i o nm e t h o d0 引 言随着航空运输业的迅猛发展,在近地面起飞㊁降落阶段,大型客机产生的噪声问题日益受到人们的关注和重视㊂国际民用航空组织(I C A O )对航空器噪声的适航标准越来越严格,对于飞越㊁横侧及近场三个测量点(分别位于与跑道中心线及其延长线相平行且距离跑道中心线450m 的边线上㊁跑道中心线的延长线上且距起飞滑跑起点6500m 处和跑道中心线的延长线上且距跑道入口2000m 处)测得的有效感知声压级(E f f e c t i v eP e r c e i v e dN o i s eL e v e l ,E P N L ),其第四阶段的有效感知声压级噪声指标要比第三阶段还要低10d B[1]㊂美国N A S A的未来航空器减噪目标要求在2020年和2050年,比目前第四阶段的适航标准有效感知声压级分别降低42d B和71d B[2]㊂欧洲的A C A R E计划也提出类似的要求,预计在2020年和2050年民机的噪声水平相比于2000年分别降低50%和65%㊂中国民航部门也针对航空器噪声提出了相应的审定标准,并写入中国民航规章第36部(C C A R-36)[3-4]㊂现代大型民用飞机的噪声水平已成为制约飞机取得适航证的关键因素之一[5]㊂因此,国内外相关单位对飞机的主要噪声源㊁噪声产生机理和控制方法开展了大量的研究㊂现代大型飞机的主要噪声源包括发动机噪声和机体噪声两大类㊂早在1970年代,G i b s o n[6-7]㊁R e v e l l[8]等人通过飞行试验测量了滑翔机㊁运输机等不同种类的飞机飞过机场时产生的噪声大小和噪声源分布,并指出机体部件是一类可能的噪声源㊂自20世纪80年代初以来,随着民用飞机大涵道比涡轮风扇发动机的广泛应用,发动机噪声已经显著下降㊂尤其在飞机起飞㊁降落阶段,起落架放下且增升装置打开,发动机处于低功率状态,此时起落架㊁增升装置等机体部件产生的气动噪声已经与飞机发动机噪声处于相同的水平,甚至超过发动机噪声[9-13]㊂因此机体噪声已经成为大型客机一类重要的噪声源㊂无论是从航空适航条例还是从舒适性㊁环保等方面来看,开展机体噪声相关问题的研究并进行相应的减噪是十分必要的㊂ D o b r z y n s k i[9]总结过去40年间国内外在飞机机体气动噪声领域的成果后指出,若按产生的噪声强度依次排列,现代大型飞机的机体噪声源包括起落架㊁前缘缝翼㊁后缘襟翼㊁襟翼侧缘㊁增升装置导轨,及扰流板和部件间的相互影响;但对于窄体飞机和支线飞机,增升装置噪声的强度几乎与起落架噪声相当㊂因此起落架噪声被认为是现代大型飞机最重要的一类机体噪声㊂本文主要综述起落架相关的气动噪声问题的研究进展㊂1起落架噪声产生机理航空部件气动噪声的研究方法主要有风洞试验㊁飞行试验㊁数值模拟和理论分析等多种方法㊂综合考虑研究成本㊁时间㊁结果精度等因素,过去几十年对起落架进行气动声学研究最常用的方法还是风洞试验㊂起落架噪声主要为宽频噪声,其产生机理包括两大类:一类是钝体分离噪声,即气流流过起落架钝体部件发生流动分离㊁再附着等流动现象而辐射的噪声;另一类是干扰噪声,即上游部件的非定常湍流尾迹作用于下游部件而产生的噪声[1,4]㊂但是主要噪声源位置和远场噪声特性与起落架构型密切相关㊂20世纪70年代末,H e l l e r和D o b r z y n s k i[14]对一个简化的两轮小车式起落架进行了远场噪声大小和指向性的测量,并分析了各个起落架部件对总噪声的贡献㊂结果表明起落架过顶方向的噪声主要产生于起落架轮胎,而侧边方向的噪声则主要来自于支撑杆部件㊂D o b r z y n s k i等人[15]在D NW-L L F风洞中对全尺寸A320和A340的前起落架和主起落架进行了试验研究,发现起落架辐射的总声压级与起落架的支柱尺寸㊁轮胎直径和支柱数目等参数密切相关,会随着支柱尺寸和数目的增加而增大㊂G u o等人[16]在L S A F 气动声学风洞中对全尺寸B737飞机的主起落架辐射的噪声进行了测量,发现起落架低频㊁中频和高频的噪声源分别为起落架轮胎㊁主支柱和细小部件㊂Y o k o k a w a等人[17]在日本R T R I风洞对40%缩放的两轮主起落架模型进行了远场噪声测量,发现两轮中间的连接轴区域是最主要的噪声源㊂L a z o s[18]测量了四轮起落架的时均流场,并指出前后两轮之间存在一个非定常的旋涡,这被认为是四轮起落架主要的噪声源㊂除了两轮和四轮起落架外,人们对现代大型宽体客机中更常见的六轮小车式主起落架构型也进行了深入的研究㊂S t o k e r[19-20]㊁H o r n e[21-22]㊁R a v e t t a[23]㊁R i n g s h i a[24]等人分别对B o e i n g777六轮小车式主起落架的缩比模型进行了试验研究,J a e g e r[25]㊁O e l e m a n s[26]㊁H u m p h r e y s[27]等人分别对其它六轮小车式起落架进行了试验研究,从他们的试验结果中,能够总结出一些非常重要的起落架噪声特点,一是起落架轮胎的数量不仅会改变低频噪声的大小,也会影响高频噪声的大小,另一个就是真实起落架上存在的小尺寸细小零部件,会产生额外的高频噪声㊂此外,起落架的安装效应会导致真实起落架与风洞试验中起落架产生的噪声存在差异㊂除试验研究外,C F D和F W-H方程相结合的混合方法㊁C A A计算气动声学等数值计算方法逐渐成为研究起落架等飞机部件气动噪声的另一类主要方法㊂X i a o等人[28]用D D E S方法模拟了四轮起落架的流场,结果显示从起落架前轮会脱落出很强的旋涡,周期性地撞击后轮,同时旋涡也会与前轮的后侧有周期性地相互作用,这些流动现象可以产生很强的辐射噪声㊂D r a g e[29]等人对简化的B747前起落架进行了数值模拟,并将得到的结果运用F W-H方程进行远场噪声的计算,他们发现对起落架的几何形状进行很小的改动,可能会导致辐射的噪声场有很大的差别㊂S o u l i e z等人[30]采用C F D和F W-H方程相结合的混合方法计算稍复杂四轮起落架的远场噪声,但是他在257空气动力学学报第35卷。
涡声理论在汽车A柱气动噪声优化中的应用
长了翅膀的小汽车的英语作文
长了翅膀的小汽车的英语作文The Flying Car: A Technological Marvel.In the realm of human ingenuity, where imagination takes flight and innovation knows no bounds, the concept of a flying car has captivated minds for centuries. From Leonardo da Vinci's visionary sketches to the futuristic renderings of modern-day engineers, the quest to create a vehicle that could soar through the skies has been an enduring pursuit. And now, thanks to the convergence of advanced technologies, that long-held dream is finally becoming a reality.The flying car, also known as an aerial vehicle, is a revolutionary concept that seamlessly integrates the capabilities of an automobile and an aircraft. It possesses the agility and maneuverability of a ground-based vehicle, allowing it to navigate the urban landscape with ease. Yet, when the need arises, it can transform into a fully-fledged aircraft, spreading its wings to ascend into the skies.The advantages of flying cars are manifold. Firstly, they offer unparalleled convenience by eliminating the limitations imposed by traffic congestion. Imagine being able to bypass gridlocked roads and soaring over dense urban areas, reaching your destination in a fraction of the time it would take by traditional means. This would not only save commuters precious hours but also reduce stress levels and improve overall quality of life.Secondly, flying cars can significantly alleviate the strain on existing transportation infrastructure. Instead of expanding roads and highways, which often requirescostly construction projects and environmental disruption, flying cars can utilize the vast expanse of airspace, reducing the need for additional ground-based infrastructure. This would not only save taxpayers money but also protect pristine ecosystems from the encroachment of human development.Moreover, flying cars have the potential to revolutionize industries such as emergency services andlogistics. In times of natural disasters or medical emergencies, aerial vehicles could provide rapid transportation to remote or inaccessible areas. They could also reduce delivery times for essential goods and supplies, ensuring that they reach their destinations quickly and efficiently.The development of flying cars is a complex and multidisciplinary endeavor that requires advancements in various fields, including aerodynamics, propulsion systems, materials science, and autonomous flight control. Engineers are constantly pushing the boundaries of innovation to create vehicles that are both safe and efficient.One of the key challenges in designing flying cars is achieving a balance between flight performance and ground maneuverability. The vehicle must be capable of generating sufficient lift to ascend into the air, while maintaining stability and control during takeoff, landing, and maneuvering. This requires careful optimization of the vehicle's aerodynamic profile, weight distribution, and propulsion system.Another critical aspect of flying car design is the development of advanced propulsion systems. Traditional gasoline engines are not suited for aircraft applications due to their high fuel consumption and limited altitude capabilities. Instead, engineers are exploring a range of alternative propulsion technologies, such as electric motors, hybrid systems, and even hydrogen fuel cells. These technologies offer greater efficiency, lower emissions, and the potential for extended flight times.Materials science also plays a vital role in the development of flying cars. The vehicle must be constructed from lightweight yet durable materials that can withstand the stresses of flight. Advanced composites, high-strength alloys, and carbon fiber are among the materials being investigated for use in flying car construction. These materials offer a combination of strength, lightness, and corrosion resistance, making them ideal for aerospace applications.Autonomous flight control systems are another essentialcomponent of flying cars. To ensure safe and reliable operation, these systems must be able to handle complex maneuvers, avoid obstacles, and maintain stable flight conditions. Advanced sensors, machine learning algorithms, and computer vision are being employed to develop sophisticated flight control systems that can operate autonomously or with minimal human input.The development of flying cars is not without its challenges. Issues such as noise pollution, air traffic management, and safety regulations need to be carefully addressed. However, with ongoing research and collaboration, these challenges can be overcome, paving the way for afuture where flying cars become an integral part of our transportation system.As the technology continues to mature, flying cars are poised to have a transformative impact on society. Theyoffer the potential to revolutionize transportation, reduce congestion, alleviate infrastructure strain, and improve emergency response capabilities. Moreover, they embody the spirit of human innovation and push the boundaries of whatis possible. The flying car is not merely a futuristic fantasy but a vision that is rapidly becoming a reality, promising to redefine the way we travel and connect with the world around us.。
整体叶盘精密电解加工工艺
埃马克电化学公司关于整体叶盘精密电解加工工艺综述面向未来的技术EMAG ECM GmbH- A PECM Cost-Saving Approach toBlisk ManufacturingEMAG ECM GmbH, 2012Abstract摘要整体叶盘的出现是为了满足市场的需求，与传统转子叶片和轮盘分离的装配式叶盘相比，由于减少了传统连接中的榫头，榫槽等装配零件，叶轮边缘负载降低，重量减轻高达30%，同时由于避免了榫头气流损失也即减少动力消耗，从而也提高气动效率并显著提高功率，有助于减少燃油消耗和废气排放。
追溯其发展历史最初应用到高压压气机以及商用压气机末端上。
是现代燃气涡轮发动机中最具创新和挑战的零部件。
The emergence of BLISK(Bladed integrated Disk) is in order to meet the market demand calls, comparing with conventional separable assembled rotor blades and disk counterparts, due to the reduction in the conventional connector assembly parts of the disk lugs, blade root groove, etc.; the rim load lower. The essential advantages are that they reduce weight up to 30% as well as reduce aerodynamic losses by avoiding disk lugs air leakage flows, thus improve aerodynamic efficiency and the power output, specially it enables reduce in fuel consumption and exhaust gas volume emissions. Retracing the history of Blisk development, it’s application initially used in high-pressure compressors and commercial compressors. It is the most innovative and challenging components of modern gas turbine engine.图1: 整体叶盘模拟图 Fig. 1: CAD Blisk市场需求情况-应对2020年需求的挑战Markt demond-Preparing for the Global Challenges of 2020European aviation is experiencing a golden age which shows no sign of slowing. The continuous growth in world air transport - passengers and freight - experienced since the 1960s is set to continue at a rate of at least 5% a year over the next two decades. The latest Airbus forecasts indicate that this will mean a demand for 7600 new aircraft every decade - or a market estimated at 1300 billion Euros by 2019. As a vital sector in the European - and American - industrial dynamic, aircraft manufacture must therefore continue to innovate if it is to win these large markets.自从1960年以来航空业一直维持每年近5%的持续的年增长率，欧洲航空空客业乐观的预测下一个12年直到2019年的平均年增长率会保持不变，这也就意味着在2020年前将会有7200架新的飞机需求（客运以及货运）/也即13000亿欧元的市场份额。
《飞行器设计》课程教学大纲
3.Able to work effectively within a team as well asindividually to solve relevant problems
9
Thrust weight ratio and wing loading
2
Lecture
Thrust weight ratio estimation methods
Wing loading estimation
Aircraft sizing methods
A5:Course work: wing sizing based on given aircraft data
13
Stability and control
2
lecture
Overview, definition and types of stability; stability analysis; aircraft control systems, aircraft flying qualities;
14
A1:Course work: analysis of several novel aircraft configuration, due in two weeks
3
Preliminary Weight estimation
2
lecture
Weight Components, Breguet Range Equation, SFC, Flight Profile, Take-off Weight Estimation, Empty Weight Estimation, Fuel Fraction Estimation, Weight of Structure Components, Fuel Tank Volume, C.G. of Various Component Groups
尾部特征参数对气动阻力交互影响与全局优化研究
尾部特征参数对气动阻力交互影响与全局优化研究作者：张勇石佳琦谷正气刘水长米承继来源：《湖南大学学报·自然科学版》2020年第02期摘要：汽车尾部结构气动减阻优化时，各几何特征参数间往往存在此消彼长的现象，使得优化变得盲目而复杂. 对此，为探明关键几何参数的交互影响规律，以Ahmed类车体为研究对象，在HD-2风洞试验对标验证基础上，对后背3个主要特征参数进行了CFD仿真研究，并在此基础上，为克服盲目性，应用集成优化平台对尾部特征参数进行优化设计. 结果表明，后背倾角角度对减阻的贡献量最大，背部两侧圆角半径次之，后背顶部圆角半径最小;三者的改变对气动阻力的影响都具有非单调性;当后背倾角角度、后背顶部圆角半径和背部两侧圆角半径分别为13°、283 mm、58 mm时，能有效减小气动阻力，减阻率达到11.76%，为具体车型减阻优化研究提供借鉴.关键词：尾部特征;交互影响;Ahmed模型;减阻中图分类号：U461.1 文献标志码：AAbstract：In the aerodynamic drag reduction optimization of automobile tail structure，there is a phenomenon between geometrical characteristic parameters，which makes optimization become blind and complex. In order to ascertain the interaction law of the key geometrical parameters，this paper carried the CFD simulation research of the three main characteristic parameters on the back of the Ahmed model on the basis of the HD-2 wind tunnel experiment. In order to overcome the blindness of optimization，the integrated optimization platform was applied to optimize the tail characteristic parameters. The results show that the angle of the back inclination has the greatest contribution to drag reduction，the two sides rounded corners on the back has the smaller contribution，the contribution of the top corner of the back is the smallest. The influence of the change of three variables on the aerodynamic resistance is non-monotonic. When the values of the angle of the back inclination，the top corner of the back and the two sides rounded corners on the back are 13°，283 mm and 58 mm respectively，the drag reduction rate reaches 11.76%. This paper provides a reference for the study of the optimization of drag reduction in specific models.Key words：tail characteristic;interaction effect;Ahmed model;drag reduction通過汽车车身三维曲面造型优化，降低气动阻力以提高燃油经济性，是汽车车身设计师的惯用方法. 然而汽车车身是由三维复杂曲面组成的片体结构，尤其是作为湍动能的主要耗散区的汽车尾部，包含了诸多曲面，每个曲面又包含诸多特征参数，改变造型特征某一参数，均会引起周围流场结构的改变，进而对气动特性产生不同影响，即存在着不同几何特征参数气动减阻优化的此消彼长的交互影响，而这种影响具有不确定性，即优化变量的盲目和未知性[1-2]，这使得车身减阻成为复杂的优化问题. 目前常用的做法只能依赖于工程师经验，开展大量重复性仿真计算基础上的部分特征参数的优化，不能保证该部位的全局最优.对此，在不改变汽车车身造型固有风格条件下，对经典的汽车模型尾部特征参数交互影响机理进行分析，开展全局优化研究，以指导具体车型开发，就显得尤为必要.Ahmed车型作为经典的斜背车体，常用于汽车空气动力学对标研究[3-6]. Thacker等[7]对其车顶与后背连接处圆角优化，减阻达到10%;Grandemange等[8]对后背倾角角度进行结构优化，使得尾部产生了4个纵向漩涡，实现整体减阻5.8%;Evrard等[9]使用基腔让尾部产生非对称湍流，减阻达9%;贺银芝等[10]指出不同后背倾角模型中气流分离特征差异较大，且阻力值随后背倾角增大而提高;倪捷等[11]在背部设置沟槽型棱纹仿生结构进行优化，使阻力值降低5%. 这些研究表明，优化尾部特征参数对减阻具有积极意义，但车体结构具有三维特征，以上研究未涉多个参数交互影响作用，因而无法保证优化参数为最优，即未获得全局最优.对此，本文以Ahmed模型为研究对象，应用数值仿真模拟，对影响尾部造型的3个主要特征参数进行气动减阻交互影响研究，并在此基础上开展全局优化.1 研究方案1.1 原始模型与风洞试验本文采用原始斜背角为25°的Ahmed 1 ∶ 1模型开展研究，其基本尺寸如图1所示（单位：mm）.为验证数值仿真方案的精度，对该模型进行HD-2风洞试验对标验证，其试验现场如图2所示.1.2 原始模型数值仿真与风洞试验验证网格划分采用四六混合网格（网格纵对称剖面如图3所示），网格数量和节点分别达到500万和200万. 仿真以ANASYS 14.0为求解器，采用隐式求解、标准壁面函数、二阶中心差分法;速度项、紊动能项和紊黏系数项采用二阶迎风差分格式. 其外流场仿真边界条件如表1所示.按图3所示的网格模型、表1所示的边界条件和K-E湍流模型进行数值仿真求解，得到该模型气动阻力系数Cd为0.305 3;按图2所示的HD-2风洞试验所测得的风阻系数为0.298 5，两者的相对误差为2.3%，表明了仿真方案的可靠性.2 交互影响研究Ahmed车型是斜背两厢车的基本模型，在保证该模型固有主体尺寸不变条件下，后背倾角角度、后背顶部圆角半径和背部两侧圆角半径3个参数影响着其流场结构. 为此本文对这3个参数的气动减阻交互效应进行研究.2.1 影响参数约束条件1）设后背倾角角度α为特征参数A. 为保持整车造型不发生太大改变，Dumas[12]给出了一个参考范围，为5°≤α≤40°.2）设后背顶部圆角半径为特征参数B. 当α角为40°且圆角倒至后背边界处时，圆角半径为812 mm，取整后变量B为50 mm ≤ B ≤ 800 mm.3）设背部两侧圆角半径为特征参数C. 根据Cheng[13]的研究，两侧边缘由棱角变为圆角时，对车辆尾部流场影响最大，为观察此影响，又考虑到车辆尺寸，变量取值范围不宜太大，定为10 mm≤C≤100 mm.3个特征参数示意图如图4所示.2.2 试验设计为辨识3个特征参数的交互影响规律，采用优化拉丁超立方法生成样本点来进行试验设计. 该方法改变了随机拉丁超立方设计的均匀性，使因子和响应拟合更为精确，且具有非常好的填充空间均衡性. 根据3个变量因子，为减小仿真过程的误差，提高模拟仿真的准确度，试验研究中取50组样本点，依据样本点生成相应的数字几何模型，分别对其进行网格划分和数值仿真计算以获得气动阻力系数Cd（数值仿真方案与1.2节相同）.在整个试验仿真研究过程中，必须经过参数化几何建模、网格划分、CFD流场计算、优化设计等过程，费时费力. 对此，基于UG二次开发实现几何模型数据交换，以脚本文件对ICEM建立自动网格划分命令，建立的操作日志文件可实现CFD边界条件、控制方程和参数调用等功能. 然后在Isight软件中[14]，采用批处理文件实现几何模型修改、网格划分、流体分析计算3个环节的数据调用、启动、关闭等操作，从而建立高效的集成优化技术. 详细过程见文献[15].2.3 交互影響分析2.3.1 阻力的交互影响分析研究特征参数对气动阻力影响，转化为对Cd的贡献量分析. 分析应分3个层次，即：独立特征参数变化对Cd的贡献量、相邻两个特征参数变化对Cd的贡献量交互效应、3个特征参数变化对Cd的贡献量交互效应.根据试验设计样本进行数值仿真，计算获得如图5所示的汽车尾部3个特征参数独立变化对气动阻力的一维贡献百分比Pareto图. 该图反映了各变量对响应Cd的贡献程度百分比，横坐标为贡献量百分比，依照不同特征参数的贡献量绝对值大小，从上至下依次排列. 由图5可见，特征参数A对气动阻力的影响为正效应，而特征参数B和C的变化对气动阻力的影响为负效应. 进一步分析为随着特征参数A的增大，引起Cd相对增大，正向影响率最大可达51%;特征参数C增大，引起Cd相对减小，最大产生负向影响可达42%;特征参数B产生的负向影响仅为7%.然而特征参数的独立变化对Cd的贡献量分析，仅表征了3种特征参数理想条件下的主次因素，而实际上3个特征参数一旦变化，必然导致造型结构的变化. 因此，应进一步分析3个特征参数之间对气动阻力Cd的交互效应.图6为A、B、C 3个特征参数两两之间的交互效应图. 其中纵坐标为模型的Cd值，横坐标为各特征参数从低到高的取值，由于3个特征参数间的取值和单位不统一，归一化后横坐标无单位量纲. 交互效应图反映了两个特征参数交互性对响应Cd的关联程度，它是在第2个特征参数取不同水平的情况下，分别绘制第1个特征参数对响应的主效应图，然后叠加而成. 如果交互效应图中的2条线相互平行，则表示这2个特征参数无交互作用;如果2条线不平行，则表示有交互作用，不平行的程度反映了交互效应的强弱. 由图6（a）（b）可见，两条线交叉，且图6（a）中2条线的不平行性更加明显，说明A与B、A与C间均存在交互效应，且A与B的交互效应更加强烈，即后背倾角与后背顶部圆角、后背倾角与背部两侧圆角均存在交互效应，且前者的交互效应更加强烈，即后风窗玻璃与上顶部夹角参数引起的Cd变化存在被其余2个特征参数分别引起的Cd变化抵消的交互效应. 图6（c）为B与C的交互效应图，图中2条线没有出现交叉，说明后背顶部圆角半径与背部两侧圆角半径的交互效应较弱.对此，本文以Ahmed模型为研究对象，应用数值仿真模拟，对影响尾部造型的3个主要特征参数进行气动减阻交互影响研究，并在此基础上开展全局优化.1 研究方案1.1 原始模型与风洞试验本文采用原始斜背角为25°的Ahmed 1 ∶ 1模型开展研究，其基本尺寸如图1所示（单位：mm）.为验证数值仿真方案的精度，对该模型进行HD-2风洞试验对标验证，其试验现场如图2所示.1.2 原始模型数值仿真与风洞试验验证网格划分采用四六混合网格（网格纵对称剖面如图3所示），网格数量和节点分别达到500万和200万. 仿真以ANASYS 14.0为求解器，采用隐式求解、标准壁面函数、二阶中心差分法;速度项、紊动能项和紊黏系数项采用二阶迎风差分格式. 其外流场仿真边界条件如表1所示.按图3所示的网格模型、表1所示的边界条件和K-E湍流模型进行数值仿真求解，得到该模型气动阻力系数Cd为0.305 3;按图2所示的HD-2风洞试验所测得的风阻系数为0.298 5，两者的相对误差为2.3%，表明了仿真方案的可靠性.2 交互影响研究Ahmed车型是斜背两厢车的基本模型，在保证该模型固有主体尺寸不变条件下，后背倾角角度、后背顶部圆角半径和背部两侧圆角半径3个参数影响着其流场结构. 为此本文对这3个参数的气动减阻交互效应进行研究.2.1 影响参数约束條件1）设后背倾角角度α为特征参数A. 为保持整车造型不发生太大改变，Dumas[12]给出了一个参考范围，为5°≤α≤40°.2）设后背顶部圆角半径为特征参数B. 当α角为40°且圆角倒至后背边界处时，圆角半径为812 mm，取整后变量B为50 mm ≤ B ≤ 800 mm.3）设背部两侧圆角半径为特征参数C. 根据Cheng[13]的研究，两侧边缘由棱角变为圆角时，对车辆尾部流场影响最大，为观察此影响，又考虑到车辆尺寸，变量取值范围不宜太大，定为10 mm≤C≤100 mm.3个特征参数示意图如图4所示.2.2 试验设计为辨识3个特征参数的交互影响规律，采用优化拉丁超立方法生成样本点来进行试验设计. 该方法改变了随机拉丁超立方设计的均匀性，使因子和响应拟合更为精确，且具有非常好的填充空间均衡性. 根据3个变量因子，为减小仿真过程的误差，提高模拟仿真的准确度，试验研究中取50组样本点，依据样本点生成相应的数字几何模型，分别对其进行网格划分和数值仿真计算以获得气动阻力系数Cd（数值仿真方案与1.2节相同）.在整个试验仿真研究过程中，必须经过参数化几何建模、网格划分、CFD流场计算、优化设计等过程，费时费力. 对此，基于UG二次开发实现几何模型数据交换，以脚本文件对ICEM建立自动网格划分命令，建立的操作日志文件可实现CFD边界条件、控制方程和参数调用等功能. 然后在Isight软件中[14]，采用批处理文件实现几何模型修改、网格划分、流体分析计算3个环节的数据调用、启动、关闭等操作，从而建立高效的集成优化技术. 详细过程见文献[15].2.3 交互影响分析2.3.1 阻力的交互影响分析研究特征参数对气动阻力影响，转化为对Cd的贡献量分析. 分析应分3个层次，即：独立特征参数变化对Cd的贡献量、相邻两个特征参数变化对Cd的贡献量交互效应、3个特征参数变化对Cd的贡献量交互效应.根据试验设计样本进行数值仿真，计算获得如图5所示的汽车尾部3个特征参数独立变化对气动阻力的一维贡献百分比Pareto图. 该图反映了各变量对响应Cd的贡献程度百分比，横坐标为贡献量百分比，依照不同特征参数的贡献量绝对值大小，从上至下依次排列. 由图5可见，特征参数A对气动阻力的影响为正效应，而特征参数B和C的变化对气动阻力的影响为负效应. 进一步分析为随着特征参数A的增大，引起Cd相对增大，正向影响率最大可达51%;特征参数C增大，引起Cd相对减小，最大产生负向影响可达42%;特征参数B产生的负向影响仅为7%.然而特征参数的独立变化对Cd的贡献量分析，仅表征了3种特征参数理想条件下的主次因素，而实际上3个特征参数一旦变化，必然导致造型结构的变化. 因此，应进一步分析3个特征参数之间对气动阻力Cd的交互效应.图6为A、B、C 3个特征参数两两之间的交互效应图. 其中纵坐标为模型的Cd值，横坐标为各特征参数从低到高的取值，由于3个特征参数间的取值和单位不统一，归一化后横坐标无单位量纲. 交互效应图反映了两个特征参数交互性对响应Cd的关联程度，它是在第2个特征参数取不同水平的情况下，分别绘制第1个特征参数对响应的主效应图，然后叠加而成. 如果交互效应图中的2条线相互平行，则表示这2个特征参数无交互作用;如果2条线不平行，则表示有交互作用，不平行的程度反映了交互效应的强弱. 由图6（a）（b）可见，两条线交叉，且图6（a）中2条线的不平行性更加明显，说明A与B、A与C间均存在交互效应，且A与B的交互效应更加强烈，即后背倾角与后背顶部圆角、后背倾角与背部两侧圆角均存在交互效应，且前者的交互效应更加强烈，即后风窗玻璃与上顶部夹角参数引起的Cd变化存在被其余2个特征参数分别引起的Cd变化抵消的交互效应. 图6（c）为B与C的交互效应图，图中2条线没有出现交叉，说明后背顶部圆角半径与背部两侧圆角半径的交互效应较弱.对此，本文以Ahmed模型为研究对象，应用数值仿真模拟，对影响尾部造型的3个主要特征参数进行气动减阻交互影响研究，并在此基础上开展全局优化.1 研究方案1.1 原始模型与风洞试验本文采用原始斜背角为25°的Ahmed 1 ∶ 1模型开展研究，其基本尺寸如图1所示（单位：mm）.为验证数值仿真方案的精度，对该模型进行HD-2风洞试验对标验证，其试验现场如图2所示.1.2 原始模型数值仿真与风洞试验验证网格划分采用四六混合网格（网格纵对称剖面如图3所示），网格数量和节点分别达到500万和200万. 仿真以ANASYS 14.0为求解器，采用隐式求解、标准壁面函数、二阶中心差分法;速度项、紊动能项和紊黏系数项采用二阶迎风差分格式. 其外流场仿真边界条件如表1所示.按图3所示的网格模型、表1所示的边界条件和K-E湍流模型进行数值仿真求解，得到该模型气动阻力系数Cd为0.305 3;按图2所示的HD-2风洞试验所测得的风阻系数为0.298 5，两者的相对误差为2.3%，表明了仿真方案的可靠性.2 交互影响研究Ahmed车型是斜背两厢车的基本模型，在保证该模型固有主体尺寸不变条件下，后背倾角角度、后背顶部圆角半径和背部两侧圆角半径3个参数影响着其流场结构. 为此本文对这3个参数的气动减阻交互效应进行研究.2.1 影响参数约束条件1）设后背倾角角度α为特征参数A. 为保持整车造型不发生太大改变，Dumas[12]给出了一个参考范围，为5°≤α≤40°.2）设后背顶部圆角半径为特征参数B. 当α角为40°且圆角倒至后背边界处时，圆角半径为812 mm，取整后变量B为50 mm ≤ B ≤ 800 mm.3）设背部两侧圆角半径为特征参数C. 根据Cheng[13]的研究，两侧边缘由棱角变为圆角时，对车辆尾部流场影响最大，为观察此影响，又考虑到车辆尺寸，变量取值范围不宜太大，定为10 mm≤C≤100 mm.3个特征参数示意图如图4所示.2.2 试验设计为辨识3个特征参数的交互影响规律，采用优化拉丁超立方法生成样本点来进行试验设计. 该方法改变了随机拉丁超立方设计的均匀性，使因子和响应拟合更为精确，且具有非常好的填充空间均衡性. 根据3个变量因子，为减小仿真过程的误差，提高模拟仿真的准确度，试验研究中取50组样本点，依据样本点生成相应的数字几何模型，分别对其进行网格划分和数值仿真计算以获得气动阻力系数Cd（数值仿真方案与1.2节相同）.在整个试验仿真研究过程中，必须经过参数化几何建模、网格划分、CFD流场计算、优化设计等过程，费时费力. 对此，基于UG二次开发实现几何模型数据交换，以脚本文件对ICEM建立自动網格划分命令，建立的操作日志文件可实现CFD边界条件、控制方程和参数调用等功能. 然后在Isight软件中[14]，采用批处理文件实现几何模型修改、网格划分、流体分析计算3个环节的数据调用、启动、关闭等操作，从而建立高效的集成优化技术. 详细过程见文献[15].2.3 交互影响分析2.3.1 阻力的交互影响分析研究特征参数对气动阻力影响，转化为对Cd的贡献量分析. 分析应分3个层次，即：独立特征参数变化对Cd的贡献量、相邻两个特征参数变化对Cd的贡献量交互效应、3个特征参数变化对Cd的贡献量交互效应.根据试验设计样本进行数值仿真，计算获得如图5所示的汽车尾部3个特征参数独立变化对气动阻力的一维贡献百分比Pareto图. 该图反映了各变量对响应Cd的贡献程度百分比，横坐标为贡献量百分比，依照不同特征参数的贡献量绝对值大小，从上至下依次排列. 由图5可见，特征参数A对气动阻力的影响为正效应，而特征参数B和C的变化对气动阻力的影响为负效应. 进一步分析为随着特征参数A的增大，引起Cd相对增大，正向影响率最大可达51%;特征参数C增大，引起Cd相对减小，最大产生负向影响可达42%;特征参数B产生的负向影响仅为7%.然而特征参数的独立变化对Cd的贡献量分析，仅表征了3种特征参数理想条件下的主次因素，而实际上3个特征参数一旦变化，必然导致造型结构的变化. 因此，应进一步分析3个特征参数之间对气动阻力Cd的交互效应.图6为A、B、C 3个特征参数两两之间的交互效应图. 其中纵坐标为模型的Cd值，横坐标为各特征参数从低到高的取值，由于3个特征参数间的取值和单位不统一，归一化后横坐标无单位量纲. 交互效应图反映了两个特征参数交互性对响应Cd的关联程度，它是在第2个特征参数取不同水平的情况下，分别绘制第1个特征参数对响应的主效应图，然后叠加而成. 如果交互效应图中的2条线相互平行，则表示这2个特征参数无交互作用;如果2条线不平行，则表示有交互作用，不平行的程度反映了交互效应的强弱. 由图6（a）（b）可见，两条线交叉，且图6（a）中2条线的不平行性更加明显，说明A与B、A与C间均存在交互效应，且A与B的交互效应更加强烈，即后背倾角与后背顶部圆角、后背倾角与背部两侧圆角均存在交互效应，且前者的交互效应更加强烈，即后风窗玻璃与上顶部夹角参数引起的Cd变化存在被其余2个特征参数分别引起的Cd变化抵消的交互效应. 图6（c）为B与C的交互效应图，图中2条线没有出现交叉，说明后背顶部圆角半径与背部两侧圆角半径的交互效应较弱.。
耦合光热发电储热-有机朗肯循环的先进绝热压缩空气储能系统热力学分析
第 12 卷第 12 期2023 年 12 月Vol.12 No.12Dec. 2023储能科学与技术Energy Storage Science and Technology耦合光热发电储热-有机朗肯循环的先进绝热压缩空气储能系统热力学分析尹航1，王强1，朱佳华2，廖志荣2，张子楠1，徐二树2，徐超2（1中国广核新能源控股有限公司，北京100160；2华北电力大学能源动力与机械工程学院，北京102206）摘要：先进绝热压缩空气储能是一种储能规模大、对环境无污染的储能方式。
为了提高储能系统效率，本工作提出了一种耦合光热发电储热-有机朗肯循环的先进绝热压缩空气储能系统(AA-CAES+CSP+ORC)。
该系统中光热发电储热用来解决先进绝热压缩空气储能系统压缩热有限的问题，而有机朗肯循环发电系统中的中低温余热发电来进一步提升储能效率。
本工作首先在Aspen Plus软件上搭建了该耦合系统的热力学仿真模型，随后本工作研究并对比两种聚光太阳能储热介质对系统性能的影响，研究结果表明，导热油和太阳盐相比，使用太阳盐为聚光太阳能储热介质的系统性能更好，储能效率达到了115.9%，往返效率达到了68.2%，㶲效率达到了76.8%，储电折合转化系数达到了92.8%，储能密度达到了5.53 kWh/m3。
此外，本研究还发现低环境温度、高空气汽轮机入口温度及高空气汽轮机入口压力有利于系统储能性能的提高。
关键词：先进绝热压缩空气储能；聚光太阳能辅热；有机朗肯循环；热力学模型；㶲分析doi： 10.19799/ki.2095-4239.2023.0548中图分类号：TK 02 文献标志码：A 文章编号：2095-4239（2023）12-3749-12 Thermodynamic analysis of an advanced adiabatic compressed-air energy storage system coupled with molten salt heat and storage-organic Rankine cycleYIN Hang1, WANG Qiang1, ZHU Jiahua2, LIAO Zhirong2, ZHANG Zinan1, XU Ershu2, XU Chao2(1CGN New Energy Holding Co., Ltd., Beijing 100160, China; 2School of Energy Power and Mechanical Engineering,North China Electric Power University, Beijing 102206, China)Abstract:Advanced adiabatic compressed-air energy storage is a method for storing energy at a large scale and with no environmental pollution. To improve its efficiency, an advanced adiabatic compressed-air energy storage system (AA-CAES+CSP+ORC) coupled with the thermal storage-organic Rankine cycle for photothermal power generation is proposed in this report. In this system, the storage of heat from photothermal power generation is used to solve the problem of limited compression heat in the AA-CAES+CSP+ORC, while the medium- and low-temperature waste heat generation in the organic Rankine cycle power收稿日期：2023-08-18；修改稿日期：2023-09-18。
理工文献检索期末试卷
一、单项选择题（从下列各题四个备选答案中选出一个正确答案，并将其代号写在答题纸相应位置处。
每题2分，共30分）1．_C_ 是题录型检索工具A. CABIB.中国学术期刊文摘C.全国报刊索引（自然版）D.经济纵横2. 浏览超星数字图书馆，应首先安装__D_____.A. Apabi ReaderB. Adobe ReaderC. CAJ ViewerD. SSReader3. 世界上第一大联机检索系统是_A_。
A.DIALOG系统B.OBRIT系统C.OCLC系统D.STN 系统4. 利用baidu搜索信息时，要将检索范围限制在网页标题中，应该使用的语法是___B_______。
A.site:B.intitle:C. inurl::5．国际农业和生物科学中心英文名称的简称为_A 。
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A. 二次检索、高级检索B.分类检索、主题检索C.数据检索、事实检索、文献检索D.计算机检索、手工检索7. 国际上评价期刊最有影响力的一个指标是___A_____。
A. 影响因子B.读者统计数据C.引文量D.价格8. 二次检索指的是：___C__________。
A．第二次检索B．检索了一次之后，结果不满意，再检索一次C．在检索结果中运用“与、或、非”进行再限制检索D.以上都不是9.国际连续出版物编号___A__________。
A.ISSNB.OCLCC.ISBND. CSSCI10．下列搜索引擎具有书名号检索功能的有______B________。
A．Google B.百度C.中搜D.AltaVista11．《中文核心期刊要目总览》2004 版的“农业经济”类核心期刊有_B__ 种。
A．20 B．19 C．17 D．1512．通过追溯检索获得的相关文献与原文献相比在发表时间上__B__。
A．早B.晚C. 相同D. 不确定13．在维普中文期刊全文数据库中“在检索结果中”检索相当于B 。
信息检索考试题汇总(附答案)
一、单项选择题（从下列各题四个备选答案中选出一个正确答案，并将其代号写在答题纸相应位置处。
每题2分，共30分）1． _C_ 是题录型检索工具A. CABIB.中国学术期刊文摘C.全国报刊索引（自然版）D.经济纵横2. 浏览超星数字图书馆，应首先安装__D_____.A. Apabi ReaderB. Adobe ReaderC. CAJ ViewerD. SSReader3. 世界上第一大联机检索系统是_A_。
A.DIALOG系统B.OBRIT系统C.OCLC系统D.STN 系统4. 利用baidu搜索信息时，要将检索范围限制在网页标题中，应该使用的语法是___B_______。
A.site:B.intitle:C. inurl::5．国际农业和生物科学中心英文名称的简称为_A 。
A.CABIB. AGRINDEXC. BAD.B of A6.信息检索根据检索对象不同，一般分为___C___________。
A. 二次检索、高级检索B.分类检索、主题检索C.数据检索、事实检索、文献检索D.计算机检索、手工检索7. 国际上评价期刊最有影响力的一个指标是 ___A_____。
A. 影响因子B.读者统计数据C.引文量D.价格8. 二次检索指的是：___C__________。
A．第二次检索 B．检索了一次之后，结果不满意，再检索一次C．在检索结果中运用“与、或、非”进行再限制检索 D.以上都不是9.国际连续出版物编号___A__________。
A.ISSNB.OCLCC.ISBND. CSSCI10．下列搜索引擎具有书名号检索功能的有______B________。
A．Google B.百度 C.中搜 D.AltaVista11．《中文核心期刊要目总览》2004 版的“农业经济”类核心期刊有_B__ 种。
A．20 B．19 C．17 D．1512．通过追溯检索获得的相关文献与原文献相比在发表时间上__B__。
叶轮机械非定常流动及气动弹性计算
中图分类号：V211.3 论文编号：1028701 18-B061 学科分类号：080103博士学位论文叶轮机械非定常流动及气动弹性计算研究生姓名周迪学科、专业流体力学研究方向气动弹性力学指导教师陆志良教授南京航空航天大学研究生院航空宇航学院二О一八年十月Nanjing University of Aeronautics and AstronauticsThe Graduate SchoolCollege of Aerospace EngineeringNumerical investigations of unsteady aerodynamics and aeroelasticity ofturbomachinesA Thesis inFluid MechanicsbyZhou DiAdvised byProf. Lu ZhiliangSubmitted in Partial Fulfillmentof the Requirementsfor the Degree ofDoctor of PhilosophyOctober, 2018南京航空航天大学博士学位论文摘要气动弹性问题是影响叶轮机械特别是航空发动机性能和安全的一个重要因素。
作为一个交叉学科，叶轮机械气动弹性力学涉及与叶片变形和振动相关联的定常/非定常流动特性、颤振机理以及各种气弹现象的数学模型等的研究。
本文基于计算流体力学(CFD)技术自主建立了一个适用于叶轮机械定常/非定常流动、静气动弹性和颤振问题的综合计算分析平台，并针对多种气动弹性问题进行了数值模拟研究。
主要研究内容和学术贡献如下：由于叶轮机械气动弹性与内流空气动力特性密切相关，真实模拟其内部流场是研究的重点之一。
基于数值求解旋转坐标系下的雷诺平均N–S(RANS)方程，首先构造了适合于旋转机械流动的CFD模拟方法。
特别的，针对叶片振动引起的非定常流动问题，采用动网格方法进行模拟，通过一种高效的RBF–TFI方法实现网格动态变形；针对动静叶排干扰引起的非定常流动问题，采用一种叶片约化模拟方法，通过一种基于通量形式的交界面参数传递方法实现转静子通道之间流场信息的交换。
景明概括恐龙飞向蓝天的演化过程的英语作文
全文分为作者个人简介和正文两个部分：作者个人简介：Hello everyone, I am an author dedicated to creating and sharing high-quality document templates. In this era of information overload, accurate and efficient communication has become especially important. I firmly believe that good communication can build bridges between people, playing an indispensable role in academia, career, and daily life. Therefore, I decided to invest my knowledge and skills into creating valuable documents to help people find inspiration and direction when needed.正文：景明概括恐龙飞向蓝天的演化过程的英语作文全文共3篇示例，供读者参考篇1The Evolution of Dinosaurs into BirdsEver since I was a little kid, I've been fascinated by dinosaurs.I loved learning about the different species, imagining what they looked like, and wondering how these giant reptiles livedmillions of years ago. However, as I grew older and studied more about paleontology, I became even more intrigued by the connections between dinosaurs and modern birds. The more I learned, the more I realized that birds didn't just descend from dinosaurs - they literally are dinosaurs, highly evolved feathered theropods that survived the mass extinction event 66 million years ago.To understand how dinosaurs evolved into birds, we first have to look at their origins and the key characteristics they share. Both dinosaurs and birds are archosaurs, a group of diapsid reptiles that first appeared around 245 million years ago during the Late Triassic period. Dinosaurs and birds have a similar bone structure, with a hole in the socket of their hip bones, amongst other similarities. However, it was feathers that provided the most compelling evidence that birds descended from dinosaurs.The late 1990s marked a pivotal turning point in our understanding of the dinosaur-bird connection. In 1996, the first feathered dinosaur fossil was discovered in northeastern China - a spectacular specimen of Sinosauropteryx, a small therapod covered in downy proto-feathers. Just a few years later in 1999, even more feathered dinosaur fossils were uncovered, includingthe iconic Archaeopteryx, which had been a object of debate for over 150 years since its discovery.With these revolutionary fossil finds, it became clear that feathers originated in dinosaurs long before the appearance of birds. Paleontologists determined that feathers likely began as simple filaments used for insulation, evolving for aerial purposes like flight much later. The famous "feathered dinosaurs" like Velociraptor and Microraptor were actually closely related to birds, providing that missing link in the dinosaur-bird transition.As more feathered dinosaur fossils were uncovered in the early 2000s, the picture became even clearer. We could now map the evolution of feathers step-by-step, starting as simpletuft-like structures, then developing into more complex branched structures, until forms indistinguishable from modern feathers emerged. We could also see related adaptations evolving, like the fusing of hand bones and the lightening of the skeletal structure to become more bird-like.Perhaps most exciting was the discovery of fossils demonstrating stages in the evolution of wings and aerial abilities. Fossils like the four-winged Microraptor showed dinosaurs experimenting with primitive forms of gliding and flying behavior. Other specimens, like the Archaeopteryx-likeAnchiornis displayed particularly bird-like skeletal adaptations suited for aerial locomotion. Dinosaurs were slowly refining their feathers and skeletal structure for eons, making that eventual transition to flight.The more I studied these incredible transitional fossils painting the dinosaur-bird picture, the more I realized that birds are the last living lineage of theropod dinosaurs. Modern birds are essentially modern feathered dinosaurs, adapted over millions of years from their carnivorous theropod ancestors into a huge variety of feathered, flying, and ecological forms.Studying the vast amount of evidence from the fossil record, it's clear that the evolutionary path from feathered dinosaurs to birds was a gradual process that unfolded over tens of millions of years, spurred by a variety of factors. Feathers first evolved for insulation purposes, giving dinosaurs an advantage in regulating body heat. As dinosaurs continued to grow larger feathers in more complex branching patterns, these feathers could have assisted in activities like thermogulation, camouflage, courtship displays, and even basic gliding or parachuting behavior.As dinosaurs started experimenting with rudimentary gliding abilities, their feathers would have become even more refined and aerodynamic, while their skeletal structure adaptedaccordingly. The skeletal changes required for aerial ability included lighter more hollow bone structures, the fusing of hand elements into a single wing structure, and an overall optimization of the body for aerial behavior. At this stage, large feathers forming wings or arm-wings were likely still being used primarily for gliding, with actual flapping flight not yet achieved.However, further refinement and adaptation of the wing structure, accompanied by the development of a more rigidly constructed shoulder girdle, allowed some dinosaurs to achieve basic flapping abilities and short bursts of powered flight. This could have proven advantageous for hunting prey, escaping predators, and other activities. As these arboreal gliding and flapping capacities developed over millions of years, some dinosaur species became more reliant and adapted to an aerial lifestyle.Eventuating around 150 million years ago in the Late Jurassic, the first species that could be properly considered "birds" emerged from these highly derived feathered theropod dinosaur lineages. These first true "birds" displayed adaptations that allowed for powered flight as a primary mode of aerial locomotion, rather than just gliding or flapping bursts. After achieving this milestone, birds continued to diversify and evolveseparate from their dinosaurian ancestors, eventually leading to the incredible variety of bird species we see today.When I think about how this incredible evolutionary transition unfolded over the course of tens of millions of years, it's truly a testament to the amazing biodiversity and adaptation capabilities life on Earth has displayed. To go from small feathered dinosaurs to the vast modern diversity of bird species is simply astonishing. Birds have evolved into masters of aerial domains, refined over eons from their humble theropod dinosaur ancestors.What once may have seemed like an improbable connection has become one of the most well-evidenced examples of evolution in the fossil record. Birds are the last living lineage of theropod dinosaurs, highly evolved feathered forms that managed to survive the mass extinction event that wiped out their other dinosaurian relatives. When I see birds taking gracefully to the skies today, I'm reminded that I'm witnessing the modern manifestation of an evolutionary process that unfolded over nearly 150 million years. Birds truly are dinosaurs, just highly specialized modern feathered theropods that managed to achieve the feat of powered flight. Even something as simple as a backyard sparrow is an incredible reminder of ourdeep evolutionary connection to dinosaurs and just how amazing the process of evolution can be on our planet.篇2The Evolution of Dinosaurs Into BirdsBy [Your Name]Ever since I was a little kid, I've been obsessed with dinosaurs. Who wasn't though, right? Those massive, lizard-like creatures have captivated our imaginations for ages. However, as I've grown older and learned more about paleontology, I've come to realize that dinosaurs aren't just fascinating remnants of the past – they're actually the ancestors of modern birds! That's right, the same feathery friends we see chirping outside our windows today can trace their origins back to the mighty dinosaurs that once ruled the Earth. Let me take you through this incredible evolutionary journey.It all started over 200 million years ago, during the Late Triassic period. At this time, a group of reptiles known as the dinosauromorpha emerged. These early dinosaur relatives were small, bipedal creatures that were well-adapted for an active lifestyle. Among them was a peculiar subgroup called theavemetatarsalians, which included early dinosaurs as well as their closest crocodilian relatives.As the Jurassic period rolled around 200-145 million years ago, avemetatarsalians diversified into two major lineages: the ornithischians (bird-hipped dinosaurs) and the saurischians (lizard-hipped dinosaurs). It was within the saurischian lineage that the true dinosaurs flourished, including the massivelong-necked sauropods and the fearsome theropods.Now, here's where things get really interesting: it was among the theropod dinosaurs that we find the earliest ancestors of modern birds. Yep, those sharp-toothed, bipedal predators like Velociraptor and T. Rex were actually the great-great-(and a few more greats)-grandparents of today's feathered friends!The first clues came in the late 20th century, with the discovery of a remarkable fossil called Archaeopteryx. This creature, which lived around 150 million years ago, had a mix of reptilian and avian features – a classic transitional form between dinosaurs and birds. With its feathered wings, wishbone, and other birdlike characteristics, Archaeopteryx provided strong evidence that birds evolved from certain theropod dinosaur ancestors.But Archaeopteryx was just the tip of the iceberg. Over the past few decades, paleontologists have unearthed a treasure trove of feathered dinosaur fossils, solidifying the evolutionary link between dinosaurs and birds. From the four-winged Microraptor to the crested Bambiraptor, these spectacular specimens have revealed how various theropod lineages independently acquired feathers and other avian traits over millions of years.So, how did this incredible transformation occur? Well, it all boils down to natural selection. Feathers, which originally evolved for insulation or display purposes, eventually became adapted for flight as certain theropod dinosaurs began experimenting with gliding behaviors. Those with more efficient feather arrangements and skeletal modifications for flight had a major survival advantage, allowing them to exploit new ecological niches and evade predators more effectively.As these bird-like dinosaurs continued to evolve and refine their flying abilities over countless generations, they gradually became more and more distinct from their ground-dwelling theropod cousins. Their bones became lighter and more hollow, their forelimbs transformed into true wings, and their tails became shorter and stiffer for improved aerial acrobatics.Finally, around 66 million years ago, a catastrophic asteroid impact wiped out all remaining non-avian dinosaurs, leaving only the highly derived avian lineages behind. These "surviving dinosaurs" – our ancestors – were able to thrive and diversify in the absence of their larger theropod relatives, eventually giving rise to the rich diversity of bird species we see today.From the majestic eagles soaring high above to the tiny hummingbirds hovering beside flowers, every single bird you encounter is a living, breathing remnant of the once-mighty dinosaur lineage. Their feathers, wings, wishbones, and other avian features are all inherited from their formidable theropod forebears, a testament to the incredible power of evolution over deep time.So, the next time you hear a bird chirping outside your window, remember – you're listening to the distant echoes of the dinosaurs that once ruled our planet. It's a humbling reminder that we share an ancient kinship with these magnificent creatures, and that the natural world is full of incredible stories waiting to be uncovered.That's the beauty of science – it allows us to peer back in time and unravel the mysteries of our planet's past, revealing connections we never could have imagined. Who knows whatother incredible discoveries await us as we continue to explore the evolutionary tapestry that has woven together all life on Earth? One thing's for sure – the journey from dinosaurs to birds is a tale that will continue to inspire awe and wonder for generations to come.篇3The Evolution of Feathered Dinosaurs into BirdsWhen I was younger, I always imagined dinosaurs as huge, scaly, lizard-like creatures that roamed the Earth millions of years ago. However, as I learned more about paleontology in school, I discovered that the evolutionary path leading to modern birds is far more fascinating than I ever could have imagined. Many dinosaurs were actually feathered, and by tracing their evolutionary lineage, we can see how these feathered dinosaurs gradually transformed over millions of years into the birds we know today.The earliest known feathered dinosaurs appeared during the Jurassic period, around 165 million years ago. Fossils from this era show small, bird-like creatures covered in primitive feathers. One of the most famous examples is Archaeopteryx, often called the first bird. With its feathered wings, light hollow bones, andother avian features, Archaeopteryx possessed a surprising mix of dinosaur and bird characteristics. While it could flap its wings, Archaeopteryx was likely not a strong flyer and spent most of its time on the ground hunting small lizards and insects.From these early feathered dinosaurs emerged the coelurosaurian theropods during the late Jurassic and into the Cretaceous period (145-66 million years ago). Coelurosaurs were a group of small to medium-sized feathered theropods more closely related to modern birds than other dinosaur groups. Velociraptor was one famous member of this lineage. Fossils reveal that coelurosaurs had lightly built skeletons with long arms and hands featuring claws useful for grasping prey. Most importantly, many coelurosaur fossils preserve clear impressions of feathers covering their bodies.As the coelurosaur lineage continued evolving, a subgroup called the Paraves emerged around 125 million years ago. Parvaves were small, feathered dinosaurs, some potentially capable of gliding or weak powered flight. Famous Paraves include the four-winged Microraptor and the crow-sized Anchiornis. These animals had long feathers forming wings on both their forelimbs and hindlimbs, providing excellent gliding abilities. While not capable of sustained flapping flight, Paravesrepresented an important transitional step as dinosaurs transformed into birds.Around 100 million years ago, Paraves diverged into two distinct lineages - the Dromaeosaurids and the Avialans. Dromaeosaurids like Velociraptor were feathered raptors that remained primarily land-based predators, while Avialans were the first dinosaurs to achieve true powered flight. Early avialans like Archaeopteryx were still very dinosaur-like, with teeth, long bony tails, and other reptilian traits. But they possessed key adaptations like powerful pectoral muscles and fused wrist bones that allowed them to flap their wing feathers and take to the skies.Over the next 10-20 million years, avialan dinosaurs gradually became more bird-like through natural selection favoring traits that enhanced aerial abilities. Their bodies grew smaller and more lightweight, with fused bones to strengthen the wings. They lost their teeth, evolving small beaks instead. Their bony tails shortened and their feathers grew more intricate for better flight. Evolutionary branches like the enantiornithines emerged around 120 million years ago as some of the first birds well-adapted for powered flight.Around 66 million years ago, a mass extinction wiped out all non-avialan dinosaur lineages. Only the avialans survived, going on to radiate into the wide diversity of modern bird species we see today. While they retained some dinosaurian features like nesting on the ground, archaeobattery birds like Vegavis from the late Cretaceous period were essentially indistinguishable from modern birds.In the 66 million years since the mass extinction, birds have evolved into over 10,000 species occupying nearly every ecological niche on the planet. They have diversified into immense variety - from tiny hummingbirds to massive ostriches, from colorful parrots to ferocious birds of prey. And yet, despite their incredible diversity of forms, all modern birds descend from those feathered dinosaur lineages that survived to fly another day.When I consider the epic evolutionary journey from small feathered dinosaurs to the vast diversity of avian species today, I am struck by both the timescale involved and the incredible specificity of adaptations required. Feathered dinosaurs like Archaeopteryx, Microraptor, and early avialans represent transition forms captured in the fossil record, visible evolutionary steps along the long path producing modern birds. Eachpossesses a novel mix of ancestral dinosaur traits combined with incipient avian adaptations.Studying the evolution of feathered dinosaurs into birds reveals the powerful persistence of life. Despite facing apocalyptic extinction events and continually adapting to changing environments over the vastness of deep time, the lineage connecting modern birds to their feathered dinosaur ancestors has remained unbroken for over 165 million years. To me, this represents one of the most awe-inspiring examples of life's ability to transform, diversify, and perpetuate itself in an ever-changing world.Understanding the dinosaurian origins of birds not only elucidates their evolutionary history, but also hints at the incredible behavioral and ecological sophistication of their prehistoric ancestors. Feathered dinosaurs engaged in complex behaviors like parental care, extensive courtship rituals, territorial defense, and even potentially simple vocal communication and flight displays - activities still observed in their modern avian descendants. Essentially, many familiar avian behaviors first emerged tens of millions of years ago in their feathered dinosaur forebears.In summary, the evolutionary transition of feathered dinosaurs into birds over 165 million years represents one of the most surprising and fascinating discoveries in paleontology. What were once perceived as distinct, unrelated groups are now understood to represent different points along an unbroken continuum. When I observe a bird soaring gracefully overhead, I no longer see just another modern creature - I perceive a direct link to the deep past, a living remnant of the feathered dinosaur lineage that once ruled the ancient Earth. To me, this underscores how the study of evolution connects all life through vast webs of genetic relationship spanning the ages. I feel privileged to understand this epic evolutionary story of how dinosaurs took to the skies and became birds.。
基于高效高精度离散伴随方法的叶轮机叶片气动优化设计
基于高效高精度离散伴随方法的叶轮机叶片气动优化设计Designing the aerodynamics of turbine blades is a crucial aspect of optimizing the performance of a turbomachinery. 叶轮机叶片气动设计是优化涡轮机性能的一个重要方面。
It is essential to achieve high efficiency and precision in the design process to ensure the overall performance of the turbine. 在设计过程中实现高效率和精度对于确保涡轮机的整体性能至关重要。
The discrete adjoint method has been widely recognized as a powerful tool for aerodynamic shape optimization due to its high efficiency and accuracy. 由于其高效性和准确性，离散伴随方法被广泛认可为气动外形优化的强大工具。
By leveraging this approach, engineers can efficiently explore a large design space and identify an optimal blade shape that minimizes aerodynamic losses while meeting structural constraints. 通过利用这种方法，工程师可以有效地探索大规模的设计空间，并识别最优的叶片形状，以最小化气动损失并满足结构约束。
One of the primary challenges in turbine blade aerodynamic optimization is the intricate interaction between the blade's geometric shape and the airflow. 涡轮机叶片气动优化的主要挑战之一是叶片几何形状与气流之间复杂的相互作用。
新型双向旋球阀工作过程动力学仿真分析
新型双向旋球阀工作过程动力学仿真分析作者：鄂加强李志鹏龚金科袁丁滕达廖灿长雷吉平来源：《湖南大学学报·自然科学版》2010年第10期摘要:针对具有双向硬密封功能的新型旋球阀的工作过程建立了动力学模型,采用Gear预估-校正算法对新型双向硬密封旋球阀工作过程动力学模型进行了求解和分析.结果表明,由于阀板的偏心结构,新型双向硬密封旋球阀开启时所需要的扭矩比关闭时所需要的扭矩要小;在水流为5 m/s的情况下,新型双向硬密封旋球阀开启时施加在轴上的扭矩不得大于5 500 N·m,关闭时施加在轴上的力不得大于4 650 N·m,否则引起水锤现象.关键词:新型双向硬密封旋球阀;水锤;动力学仿真分析;硬密封中图分类号:TK730.4 文献标识码:ADynamic Simulation and Analysis of the Work Process of a NewType Rotating Ball Valve with Double Direction Metal SealingE Jia qiang1,2, LI Zhi peng2, GONG Jin ke1, YUAN Ding2, TENG Da2, LIAO Can zhang2, LEI Ji ping 2(1.College of Mechanical and Vehicle Engineering, Hunan Univ, Changsha, Hunan 410082, China; 2.Hunan Pump and Valve Manufacturing Co Ltd, Changsha, Hunan 410007, China)Abstract: A dynamic model of the work process of a new type rotating ball valve with double direction metal sealing was established. And the dynamic model was simulated and analyzed by using Gear Predictor Corrector Algorithm. The results of dynamic simulation and analysis revealed that the torsion of turning on the new type rotating ball valve was less than the torsion of closing up the new type rotating ball valve. And in order to avoid water hammer, the torsion of turning on the new type rotating ball valve should be less than or equal to 5 500 N·m, and the torsion of closing up the new type rotating ball valve should be less than or equal to 4 650 N·m, when the velocity of flowing water was 5 m/s.Key words: new type rotating ball valve with double direction metal sealing; water hammer; dynamic simulation and analysis; metal sealing阀门是管道流体输送系统中应用最广泛最重要的执行机构或者控制元件[1-3],主要具有接通或截断流体通路、调节与节流、防止倒流、调节压力或释放过剩的压力等5大功能,可以控制空气、水、各种腐蚀性化学介质,泥浆、液态金属和放射性物质等各种类型的流体的流动,在国民经济各个部门中有着广泛的应用.然而在新型阀门开发能力方面,掌握的水力模型少,在强度、刚度、启闭、振动和可靠性设计方面还存在一定的差距.尽管国外已将计算流体力学、有限元结构与旋转动力学分析、新型的信息管理与应用技术应用于阀门的设计、应用与实际操作[4-6],但阀类机械的设计还停留在“设计-试制-试验-改进”的阶段,实用性较差,对存在的问题和故障现象提出解决办法,但都未从根本上解决存在的问题[7-10].仍然存在加工更为复杂、工序多、合格率低、大规模生产制造困难,加工成本较高和使用寿命短等缺点.因此,研究开发长寿节能节水的新型双向流旋球阀显得十分重要.要开发出新型长寿节能节水的双向硬密封旋球阀,就必须优化新型双向硬密封旋球阀的动力结构从而改善其动力性能,而新结构、新材料的介入,是否能使其性能更好,需要做大量复杂的分析工作,ADAMS为新型双向硬密封旋球阀动态性能分析提供了很好的研究平台[11-13].本文基于ADAMS技术对新型双向硬密封旋球阀工作过程进行动态特性仿真,其研究结果对于新型长寿节能节水的双向流旋球阀开发具有十分重要的指导意义.1 新型双向硬密封旋球阀工作原理新型双向流旋球阀总体结构类似蝶阀结构,分为阀体总成(包括阀体和阀座)和阀板总成(阀板、阀杆和阀杆端密封件、驱动机构).阀板密封面类似球阀,为正球面,相当于球体两端直接切除余下的部分.阀板固定于阀杆上,在外部驱动机构作用下,围绕阀杆轴线转动,作为阀门启、闭件.阀座不与阀体连为一体,为单独的零件,在介质作用下可沿阀体轴线移动.阀座密封面为圆环锥面,阀门关闭时密封面为线接触密封.阀芯的密封面为三次曲面,阀座的密封面为一次圆锥面.在密封点处,阀座面实际上是阀芯三次曲面的切面,具有自适应(中心自动定位重合)和补偿磨损功能.因为转动中心偏离阀芯几何中心,当阀芯打开时,阀芯实体不断向后退、向内缩;当阀芯关闭时,阀芯实体不断向前进、向外胀,其结构与功能相当于半球阀、闸阀、截止阀和蝶阀的综合结构与功能,阀芯实体各不同角度的变化如图1所示.(a) 0° (b) 30° (c) 45° (d) 90°新型双向流旋球阀在正向压力时密封良好,在反向压力或反向压力大于正向压力时密封也良好.当正向压力作用时,介质压力推动阀板向前移动,阀杆变形,阀板密封面紧贴阀座密封面传递压力,将阀座推向阀体台阶,使之密封良好;当反向压力作用时,介质压力推动阀板向后移动,介质压力同时推动阀座向后移动,阀座密封面紧贴阀板密封面传递压力,将阀座推向阀杆极限变形位置,使其密封良好.正、反向阀座密封示意图如图2所示.(a) 正向流 (b) 反向流2 新型双向硬密封旋球阀动力学仿真2 1 新型双向硬密封旋球阀动力学方程新型双向硬密封旋球阀动力学系统可以由非自由质点系表示.用刚体i的质心笛卡尔坐标和反映刚体方位的欧拉角作为广义坐标q i=[x, y, z, Ψ, θ, φ]T i,对于有n个刚体的新型双向硬密封旋球阀动力学系统,即q=[q T1, q T2, …,式中T为系统动能;q为系统广义坐标列阵;Q为广义力列阵;ρ为对应于完整约束的拉氏乘子列阵;u为对应于非完整约束的拉氏乘子列阵;φ(q, t)为完整约束方程;θ(q, , t)为非完整约束方程,为广义速度列阵.令u=,把式(1)降阶为一阶代数微分方程组并改写成更一般的形式:式中λ为约束反力及作用力列阵;F为系统动力学微分方程及用户定义的微分方程(如用于控制的微分方程、非完整约束方程);Φ为描述约束的代数方程列阵.如定义系统的状态矢量y=[q T, u T, λT]T,式(2)可写成单一矩阵方程:2 2 新型双向硬密封旋球阀的动力学仿真算法在进行新型双向硬密封旋球阀动力学仿真分析时,采用Gear预估-校正算法,其主要求解步骤是:预测、迭代校正、积分误差分析、对积分步长和积分多项式阶的优化.首先根据当前时刻的系统状态矢量值,用泰勒级数预估下一时刻系统的状态矢量值:这种预估算法得到的新时刻的系统状态矢量值通常不准确,式(2)右边的项不等于零,可以由Gear+1阶积分求解程序(或其他向后差分积分程序)来校正.如果预估算法得到的新时刻的系统状态矢量值满足式(2),则可以不必进行校正.式中左边的系数矩阵称系统的雅可比矩阵,其中F/q为系统刚度矩阵;F/u为系统阻尼矩阵;F/为系统质量矩阵.通过分解系统雅可比矩阵求解Δq j,Δu j,Δλj,计算出校正步骤,直到满足收敛条件若预估值与校正值的差值小于规定的积分误差限,接受该解,进行下一时刻的求解.否则拒绝该解,并减少积分步长,重新进行预估-校正过程.总之,微分-代数的求解算法是重复估计、校正、进行误差控制的过程,直到时间达到规定的模拟时间.2 3 新型双向硬密封旋球阀工作过程动力学模型2.3.1 运动机构动模型的输入在进行新型双向硬密封旋球阀运动机构动模型的输入时,在UG中使用[文件]-[导出]-[Parasolid]-[框选需要的组件]命令,将三维模型另存为Parasilid格式.然后打开ADAMS/View,在初始界面中选择[Import a file],选择格式和地址,将文件导入ADAMS/View中,点击[Apply],就得到如图3(a)所示的初步的动力学仿真模型.以这种方法输入可以保证输入正确的装配关系和正确的模型与重力场的角度关系.2.3.2 运动模型的约束约束的类型:建立新型双向硬密封旋球阀动力仿真模型时,可以通过各种约束限制构件之间的某些相对运动,并以此将不同构件连接起来组成一个机构系统.ADAMS/View可以处理以下4种类型的约束:①用运动副约束,例如转动副、移动副等;②指定约束方向,即限制某个运动方向,例如限制一个构件总是沿着平行于另一个构件的方向运动;③接触约束,定义两构件在运动中发生接触时,是怎样相互约束的;④约束运动,例如规定一个构件遵循某个时间函数按指定的轨迹规律运动.新型双向硬密封旋球阀运动模型的约束:根据双向流实体硬碰硬密封旋球阀运动模型的运动要求,其需要的约束主要有:①固定副.约束3个旋转3个移动自由度,如阀体与大地的连接;②旋转副.约束2个旋转3个移动自由度,如阀轴与阀体的连接.施加约束后的新型双向硬密封旋球阀运动模型如图3(b)所示.新型双向硬密封旋球阀运动模型的约束副为2个,固定副1个,旋转副1个.2 4 新型双向硬密封旋球阀动力学仿真分析新型双向硬密封旋球阀的阀板直径为805 mm,水流的速度为5 m/s,经过计算,把水流作用在阀板上的力集中在阀板两侧以阀轴的轴线为对称线的两点上,大小分别为F1=1 000 N,F2=900 N,施加在轴上的扭矩为M=900 N·m,根据实际情况,设关闭仿真时间为0.5 s,开启仿真时间为0.6 s,抗水锤仿真时间为0.1 s.2.4.1 关闭过程的动力学仿真分析阀门关闭时,施加在新型双向硬密封旋球阀上的力有水流的冲击力和在阀轴上的旋转力矩.由于阀门的偏心结构,所以阀板的两边所受到的水流的冲击力是不相等的(大边所受的力大),但方向相同,都为垂直于阀板关闭时所在的平面.新型双向硬密封旋球阀关闭过程的动力学仿真结果如图4所示.图4中阀板的角速度曲线、速度曲线和位置曲线表明,关闭过程中阀板的运动比较平缓,没有出现极速冲击;而阀轴在Z轴的位置曲线有很小波动,说明在加工和装配过程中会出现一些误差,应设法减小这些误差.阀门开启时,在新型双向硬密封旋球阀上的反向施加水流的冲击力和阀轴上的旋转力矩.由于阀门的偏心结构,所以阀板的两边所受到的水流的冲击力是不相等的,但方向相同,都为垂直于阀板开启时所在的平面,仿真结果如图5所示.图5中阀板的角速度曲线、速度曲线和位置曲线同样表明,开启过程中阀板的运动比较平缓,没有出现极速冲击;而阀轴在Z轴的位置曲线有很小波动,说明在加工和装配过程中会出现一些误差,应减少这些误图4和图5中的角速度曲线、速度曲线表明,在同样的扭矩下,开启时的角速度、速度要比关闭时的角速度、速度大,这主要由阀板的偏心结构所引起的.因此,新型双向硬密封旋球阀开启时所需要的扭矩比新型双向硬密封旋球阀关闭时所需要的扭矩要小一些.当打开的阀门突然关闭,水流对阀门及管壁,主要是阀门会产生一个压力.由于管壁光滑,后续水流在惯性的作用下,迅速达到最大,并产生破坏作用,这就是水利学当中的“水锤效应”,也就是正水锤.相反,关闭的阀门在突然打开后,也会产生水锤,叫负水锤,也有一定的破坏力,但没有前者大.在新型双向硬密封旋球阀开启的仿真中,通过不断增加阀轴上的扭矩,观察阀板的速度曲线,当水流速度不变时(即阀板上的力不变时),阀轴的扭矩达到 5 500 N·m时得到发生水锤现象时阀板的速度曲线和位移曲线如图6所示.同理,在新型双向硬密封旋球阀关闭时,当扭矩达到4 650 N·m时,也发生水锤现象,图7分别为发生水锤现象时的阀板的速度曲线和位移曲线.由图6和图7可以看出,阀板在很短的时间里开启,其边缘点在Z轴方向上的速度在很短的时间里达到了1 500 m/s,产生了极速冲击.所以应控制好新型双向硬密封旋球阀开启和关闭时所施加的力矩,尽量使阀板旋转平缓,此外也可控制水流的速度,不应使水流的速度过大.3 结论1)由于阀板的偏心结构设计,故新型双向硬密封旋球阀开启时所需要的扭矩比其关闭时所需要的扭矩要小.2)在水流为5 m/s的情况下,新型双向硬密封旋球阀开启时,施加在轴上的扭矩不得大于5 500 N·m;在其关闭时,施加在轴上的力不得大于 4 650N·m,否则阀板转速过快,水流急速冲击阀板从而产生水锤现象.3)动力学仿真分析表明,基于ADAMS的动态特性仿真,可以有效提高新型双向硬密封旋球阀仿真建模和分析的效率.参考文献[1] CHERN Ming jyh, WANG Chin cheng, MA Chen hsuan. Performance test and flow visualization of ball valve[J]. Experimental Thermal and Fluid Science, 2007, 31(6): 505-512.[2] PARK Ju yeop, CHUNG Myung kyoon. Study on hydrodynamic torque of a butterfly valve[J]. Journal of Fluids Engineering, 2006, 128(1): 190-195.[3] VETTER J, MICHLER T, STEUERNAGEL H. Hard coatings on thermochemically pretreated soft steels: application potential for ball valves[J]. Surface and Coatings Technology, 1999, 111 (2/3): 210-219.[4] SONG Xue guan, WANG Lin, SEOK Heum baek,et al. Multidisciplinary optimization of a butterfly valve[J]. ISA Transactions, 2009, 48(3): 370-377.[5] DANBON F, SOLLIEC C. Aerodynamic torque of a butterfly valve influence of an elbow on the time mean and instantaneous aerodynamic torque[J]. Journal of Fluids Engineering, 2000,122(2): 337-344.[6] TIAN Wen xi, SU G H, WANG Gao peng,et al. Numerical simulation and optimization on valve induced water hammer characteristics for parallel pump feedwater system[J]. Annals of Nuclear Energy, 2008, 35(12): 2280-2287.[7] ATASHKARI K, NARIMAN ZADEH N, GLCM, et al. Modelling andmulti objective optimization of a variable valve timing spark ignition engine using polynomial neural networks and evolutionary algorithms[J]. Energy Conversion and Management, 2007,48(3): 1029-1041.[8] HUMMER G, HALTER G, GR SSL M. Calculated and measured flow conductance for butterfly valves[J]. Vacuum, 1990, 41(7/9): 2126-2128.[9] JONES Chris, WALDON Chris, MARTIN David, et al. Conceptual design of a compact absolute valve for the ITER neutral beam injectors[J]. Fusion Engineering and Design, 2009, 84(2/6): 979-984.[10]LIN Judy L, CLEVENGER Jason M. Modeling and optimizing passive valve designs for the implantable gold micro shunt used in glaucoma treatment[J]. Computers & Structures, 2009,87(11/12): 664-669.[11]HARISH Agarwal, JOHN E Renaud, EVAN L Preston, et al. Uncertainty quantification using evidence theory in multidisciplinary design optimization [J]. Reliability Engineering &System Safety, 2004, 85(1/3): 281-294.[12]刘静,潘双夏,冯培恩. 基于ADAMS的挖掘机液压系统仿真技术[J]. 农业机械学报,2005,36(10):109-112.LIU Jing, PAN Shuang xia, FENG Pei en. Study on simulation technology of excavator hydraulic system based on ADAMS[J]. Transactions of the Chinese Society for Agricultural Machinery, 2005,36(10): 109-112.(In Chinese)[13]王国强,张进平,马若丁. 虚拟样机技术及其在ADAMS上的实践[M]. 西安:西北工业大学出版社,2002.WANG Guo qiang, ZHANG Jin ping, MA Ruo ding. Technology of virtual models and its application on ADAMS[M]. Xi’a n: Northwestern Polytechnical University Press, 2002. (In Chinese)。
高效气动优化设计方法
高效气动优化设计方法傅林;左英桃【期刊名称】《航空计算技术》【年(卷),期】2012(042)004【摘要】基于CFD方法开展气动外形优化设计通常计算量较大,采用离散共轭方法计算目标函数梯度,建立了高效的飞机气动优化设计系统.采用NURBS方法对翼剖面几何外形的扰动量进行参数化,避免了对原始外形的拟合,建立了基于NURBS 方法的机翼剖面参数化方法.在复杂外形的优化设计中,动网格方法是关键技术之一,采用无限插值方法生成变形后的网格,并提出采用无限插值方法处理部件之间相贯线发生变化的情况.最后开展了翼身组合体+吊舱+挂架等复杂外形的优化设计,成功地减小了阻力,证明了方法的有效性.%Large scales of computations are required in aerodynamic optimization based on CFDmethodologies.Efficient aerodynamic design optimization system is built in this paper,and the gradients of object functions are calculated with discrete adjoint method.The geometric perturbations of wing sections are parameterized with NURBS method,furthermore parameterization methodology of wing based on NURBS are built.Moving grid is one of key technologies in aerodynamic optimization design of very complex configuration.Transfinite interpolation methodology is utilized to generate new grid, and a methodology based on transfinite interpolation technology is proposed to deal with the surface grid in the case of junction lines varying.Configurations including wing - body - nacelle - pylon areoptimized with the design optimization system.The drag is reduced successfully, which illustrates the effectiveness of the methodology built in this paper.【总页数】5页(P68-71,76)【作者】傅林;左英桃【作者单位】西北工业大学翼型、叶栅空气动力学国防科技重点实验室,陕西西安710072;西北工业大学翼型、叶栅空气动力学国防科技重点实验室,陕西西安710072【正文语种】中文【中图分类】V211.3【相关文献】1.一种计及静气动弹性变形影响的跨声速机翼气动优化设计方法研究 [J], 熊俊涛;乔志德;杨旭东;朱标2.基于优化设计方法的超高负荷增压级气动设计 [J], 薛伟伟;周正贵3.旋翼翼型中高速综合气动优化设计方法研究 [J], 陈笑天; 吴裕平; 田旭4.低雷诺数翼型多点气动优化设计方法研究 [J], 李帝辰;杨龙;魏闯;张铁军5.自重构变形桨叶螺旋桨气动推进优化设计方法 [J], 凌付平;秦黄辉因版权原因，仅展示原文概要，查看原文内容请购买。
高空长航时无人机技术发展新思路
高空长航时无人机技术发展新思路段海滨;范彦铭;张雷【期刊名称】《智能系统学报》【年(卷),期】2012(7)3【摘要】根据未来航空发展的战略需要,面向新一代高空长航时无人机的系统设计,十分有必要开展探索性、创新性和面向高空长航时无人机的关键技术研究.提出了高空长航时无人机技术发展的新思路和其瓶颈问题的解决方案.重点从高空长航时无人机多目标组合优化、气动-隐身一体化、能源动力、软件使能自主控制、自主导航、测控和信息传输、空天地多机分布协同等方面给出了可行技术方案和重点研究方向.这些技术的实现可增强高空长航时无人机系统方面的可持续发展能力,支撵和引领相关领域的技术发展.%According to the strategic requirements of future aviation development, and considering system design for the new generation of high-altitude and long-endurance (HALE) unmanned aerial vehicles (UAVs) , it is necessary to develop exploratory, innovative, and key technologies for HALE UAVs. In this paper, some new ideas were proposed for HALE UAVs which mainly focus on multi-objective optimization, integrated design of aerodynamic and stealthy performance, energy and power, software-enabled control, autonomous navigation, measurement and control systems, information transmission, and multi-platform distributed cooperation. The proposed technologies can enhance the capacity of HALE UAV systems for sustainable development, and support the developments in other relevant technical areas.【总页数】5页(P195-199)【作者】段海滨;范彦铭;张雷【作者单位】北京航空航天大学自动化科学与电气工程学院,北京100191;北京航空航天大学飞行器控制一体化技术重点实验室,北京100191;中国航空工业集团公司沈阳飞机设计研究所,辽宁沈阳110035;中国人民解放军空军装备部,北京100843【正文语种】中文【中图分类】TP273【相关文献】1.工程机械焊接技术发展与创新思路 [J], 王明2.探析金属材料力学性能检测技术发展的新思路 [J], 王方3.高速铁路信号系统联调联试技术发展新思路 [J], 禹志阳;陈晓明;霍黎明4.工程机械焊接技术发展与创新思路 [J], 阴世悦5.工程机械焊接技术发展与创新思路 [J], 贾春帅因版权原因，仅展示原文概要，查看原文内容请购买。