多介质计算书

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多层介质传热的计算模拟

Applied Physics 应用物理, 2019, 9(1), 7-12 Published Online January 2019 in Hans. /journal/app https:///10.12677/app.2019.91002
摘
*
要
在稳定热源流过多层介质材料的传热过程中，温度会随时间和位置发生变化。本文分析了稳定热源通过
通讯作者。
文章引用: 甄嘉鹏, 郭琦, 周江. 多层介质传热的计算模拟[J]. 应用物理, 2019, 9(1): 7-12. DOI: 10.12677/app.2019.91002
甄嘉鹏等
多层介质传热的温度分布，运用热传导方程导出了热稳定后的温度分布以及最内层材料温度随时间的变化关系。本文的方法适用于多种隔热材料的复合问题，可求出多层介质各层温度随时间的变化规律。
Keywords
Multi-Layered Media, Heat Transfer, Thermal Insulation Material
多层介质传热的计算模拟
甄嘉鹏1，郭
1 2
琦2，周
江1*
贵州大学物理学院，贵州贵阳贵州大学数学与统计学院，贵州贵阳
收稿日期：2018年12月21日；录用日期：2019年1月4日；发布日期：2019年1月11日
由傅里叶定律和能量守恒定律得出温度随时间和位置变化的方程[8]：
Open Access
1. 引言
多层材料在传热过程中，不同介质材料会导致不同的温度分布。温度在材料内部随着位置而变化，材料最内侧的温度会随热传递的时间而变化。这类问题从 20 世纪 80 年代开始一直被广泛研究。 1981 年，顾延安研究了保温层外壁面温度，以及它的计算方法，通过理论推导给出了一种计算热损失的方法[1]。 2007 年，白净选用第一类边界条件下的柱坐标形式的导热微分方程对圆筒壁内的温度分布进行计算和分析，得出结论等温面的热流密度相同[2]。曾剑等考虑了一类热传导方程中间断扩散系数的反问题，证明了时间相对较小时，极小元的唯一性和稳定性[3] [4] [5] [6]。2018 年，陈大伟利用热传导方程的差分格式对一维热传导方程的数值解进行计算并绘成图，从而直观地得到热传导媒介上的温度时空分布[7]。目前，对于热传导方程解的研究并以此得到热传导媒介在传热过程中的温度分布的相关研究仍在继续，然而对于将两者与隔热材料相结合以提高复合材料的隔热性能以及对隔热时间的研究仍然较少。该研究对于复合材料隔热性能的提高和隔热材料的选择具备参考价值，在实际生活中的应用也较为广泛，可应用于高温作业服、消防隔热墙等诸多领域，因此具有一定的研究价值。本文通过实验所得实验数据，利用数学物理方程建立稳定状态下的温度分布模型，包括复合介质各分界面的温度变化和多层材料内侧温度随时间的变化。将该热传导模型和实验曲线进行对比，验证模型的正确性。

一维多介质可压缩流动数值方法

一维多介质可压缩流动数值方法
一维多介质可压缩流动数值方法
应用高精度界面追踪方法计算一般状态方程的多介质可压缩流动问题;应用Level Set技术捕捉界面位置,在界面附近采用守恒数值离散,用双波近似求解一般状态方程Riemann问题,并采用统一高阶PPM格式进行内点和交界面点的计算.一维算例表明,该方法对于光滑区域以及多介质交界面具有二阶精度,能准确地模拟交界面的位置,交界面计算无数值振荡和数值耗散,并能处理一般状态方程的多介质可压缩流动问题.
作者：马东军孙德军尹协远作者单位：中国科技大学力学和机械工程系,安徽,合肥,230027 刊名：计算物理 ISTIC EI PKU 英文刊名： CHINESE JOURNAL OF COMPUTATIONAL PHYSICS 年，卷(期)： 2003 20(2) 分类号： O354 O241 关键词：多介质可压缩流动一般状态方程界面追踪方法高阶Godunov格式。

中水回用系统-计算书111212

中水回用系统主要设施计算书1.曝气生物滤池设计中水处理量250m3/h，设计进水COD 150mg/L 出水COD 60mg/L，约定COD进水负荷:1。

5kgCOD/m3·d，则BAF所需的有效容积为:QS/N V=250＊24*150/1000/1。

5=600m3，鉴于本池需要具有较高的碳化和硝化效果,设计滤料高度为3m，则BAF所需面积为A= 600/3=200m2,考虑池体单格不宜过大，设置为四格,利于运行。

则单格面积为200/4=50m2。

校核以下参数：COD去除负荷：0.9kgCOD/m3·d，小于规范设计要求。

BOD负荷：设计进水BOD：30mg/L，出水BOD：10mg/L校核BOD去除负荷：0.2kgBOD/m3·d设计进水NH3-N：30mg/L，出水NH3—N：10mg/LNH3-N设计去除负荷:0.2kgNH3-N/m3·d校核滤池表面水力负荷（滤速)m3/m2·h（m/h)：1。

25，低于规范的2.5。

空床水力停留时间（有效)：2.4h，大于规范要求。

上述参数均属于合适的范围。

曝气量的确定：①碳化和硝化需氧量设计取值为:1。

4kgO2/kgCOD,4.6kgO2/kgNH3—N则总需氧量为：250*（150-60）/1000＊1。

4+250＊（30—10）/1000＊4.6=54。

5kgO2/h 所需空气量为54。

5/0。

21/0。

10/60=43.25m3/min，取为43m3/min。

②校核气水比气水比为43*60/250=10.3，大于8，符合。

空气冲洗强度：66m3/m2·h，则所需反冲洗气量：66＊50/60=55m3/min。

水冲洗强度：22m3/m2·h；则所需反冲洗水量：22*50=1100m3/h，设计为3台泵，2用1备,单台流量550m3/h,扬程取为15m。

设计尺寸：单格L=8。

常用介质的设计计算

4、点击计算按钮输出结果：
5、点击 “计算书”按钮，软件自动生成计算书
十一、十一、管道损失计算
1、打开软件，手动输入流量、管道内径、管道长度、介质密度、当量粗糙度及运动粘度
2、运动粘度的调取：各种参数-水的运动粘度
3、点击“ok”，自动计算出管路沿程阻力
4、调取局部阻力系数，根据管路上的管件数计算局部阻力系数（加和）
七、保温层经济厚度计算
1、打开保温层经济厚度计算软件，选择保温材料
2、选择保温管线公称直径
3、选择保温管线介质温度，随后软件将自动计算出经济厚度。
八、过热蒸汽温降计算
顺序将处于 “输入”前的数据框中的数据进行手动输入，没有“输入” 标示的位置为软件自动生成。
九、水管管道阻力计算
3、按照推荐的介质流速手动输入选择的流速
4、手动输入介质流量和介质比容
5、点击计算按钮，软件将自动输出其它数据：管道内径及其最大和最小值
6、设计中还需考虑留有一定的余量，自行把握。
五、管件当量计算
1、在蓝色阴影区手动输入管道外径和内径：如、426 和13（注意单位）
101209
水、蒸汽常用物性数据补充查询——潜热
二、量和单位转换
1、打开量和单位转换软件：
2、点击石油化工按钮：
3、选择动力粘度，在单位为CP中输入1
4、软件自动输出其它单位数据：
5、同理选择运动粘度（除此之外的导热系数也是比较重要）厘斯：mm2/s
6、选择粘度转换——动力粘度-运动粘度
7、在弹出的对话框中手动输入动力粘度数据：如25℃时水的粘度值。
2、在换热器形式中选择将要校核的换热器形式：（见各种换热器形式动画）

Fluent计算多孔介质模型资料

广东省深圳市宝安区沙井辛养社区西部工业园 TEL:+86-755-3366-8888 FAX:+86-755-3366-0612Fluent计算多孔介质模型资料这是一个多孔介质例子，进口速度为0.01m/s,组份为液态水和氧气，其中氧气从多孔介质porous jump 渗透过去，如何看氧气在tissue中扩散的。

porous jump的face permeability1 a=e-8 m_2thickness 设为0.0001pressure jump coefficient为默认porous zone设置如下：direction vector 1, 1,viscous resistance 100 eachinertial resistance 100 eachporosity 0.1边界条件设置如下：Ab – wall - defaultBc – wall – defaultBe – porous jump – face permeability 1e-8, porous medium thickness0.0001Cd – outflow rating – 0.5De – wall – defaultDefault interior – interiorDefault interior001 – interiorDefault interior019 – interiorEf – wall - defaultFg – outflow rating – 1Fluid - porous zone - direction vector 1, 1, viscous resistance 100 each,inertial resistance 100 each, porosity 0.1Gh- wall - defaultHi – wall - defaultHk - porous jump same conditions as otherIj – outflow – 0.5Jk – wall – defaultKl – wall – defaultLa – velocity inlet – 0.01 m/s, temperature 300K, 0.5 mass fraction O2 Lfluid – porous zone - direction vector 1, 1, viscous resistance 100 each,inertial resistance 100 each, porosity 0.1Pipefluid – fluid – default (no porous zone)Models – species transport – water and oxygen mixtureVariations – different boundary conditions at top and bottom (outflow, wall ect)注意,其中porous zone在gambit中设置为fluid，在fluent中设置为porous zone边界条件设置如下：Ab – wall - defaultBc – wall – defaultBe – porous jump – face permeability 1e-8, porous medium thickness0.0001Cd – outflow rating – 0.5De – wall – defaultDefault interior – interiorDefault interior001 – interiorDefault interior019 – interiorEf – wall - defaultFg – outflow rating – 1Fluid - porous zone - direction vector 1, 1, viscous resistance 100 each,inertial resistance 100 each, porosity 0.1Gh- wall - defaultHi – wall - defaultHk - porous jump same conditions as otherIj – outflow – 0.5Jk – wall – defaultKl – wall – defaultLa – velocity inlet – 0.01 m/s, temperature 300K, 0.5 mass fraction O2 Lfluid – porous zone - direction vector 1, 1, viscous resistance 100 each,inertial resistance 100 each, porosity 0.1Pipefluid – fluid – default (no porous zone)Models – species transport – water and oxygen mixtureVariations – different boundary conditions at top and bottom (outflow, wall ect) 注意,其中porous zone在gambit中设置为fluid，在fluent中设置为porous zone。

fluent中多孔介质设置问题和算例

经过痛苦的‎一段经历，终于将局部‎问题真相大‎白，为了使保位‎同仁不再经‎过我之痛苦‎，现在将本人‎多孔介质经‎验公布如下‎，希望各位能‎加精：1。

Gambi‎t中划分网‎格之后，定义需要做‎为多孔介质‎的区域为f‎l uid,与缺省的f‎l uid分‎别开来，再定义其名‎称，我习惯将名‎称定义为p‎o rous‎;2。

在flue‎n t中定义‎边界条件d‎e fine‎-bound‎a ry condi‎t ion-porou‎s(刚定义的名‎称)，将其设置边‎界条件为f‎l uid,点击set‎按钮即弹出‎与f lui‎d边界条件‎一样的对话‎框，选中por‎o us zone 与‎l a min‎a r复选框‎,再点击po‎r ous zone标‎签即出现一‎个带有滚动‎条的界面；3。

porou‎s zone设‎置方法：1）定义矢量：二维定义一‎个矢量，第二个矢量‎方向不用定‎义，是与第一个‎矢量方向正‎交的；三维定义二‎个矢量，第三个矢量‎方向不用定‎义，是与第一、二个矢量方‎向正交的；（如何知道矢‎量的方向：打开gri‎d图，看看X,Y,Z的方向，如果是X向‎，矢量为1,0,0,同理Y向为‎0,1,0，Z向为0,0,1,如果所需要‎的方向与坐‎标轴正向相‎反，则定义矢量‎为负）圆锥坐标与‎球坐标请参‎考f lue‎n t帮助。

2）定义粘性阻‎力1/a与内部阻‎力C2：请参看本人‎上一篇博文‎“终于搞清f‎l uent‎中多孔粘性‎阻力与内部‎阻力的计算‎方法”，此处不赘述‎；3）如果了定义‎粘性阻力1‎/a与内部阻‎力C2,就不用定义‎C1与C0‎，因为这是两‎种不同的定‎义方法，C1与C0‎只在幂率模‎型中出现，该处保持默‎认就行了；4）定义孔隙率‎p o rou‎s ity，默认值1表‎示全开放，此值按实验‎测值填写即‎可。

完了，其他设置与‎普通k-e或RSM‎相同。

总结一下，与君共享!Tutor‎i al 7. Model‎i ng Flow Throu‎g h Porou‎s Media‎Intro‎d ucti‎o nMany indus‎t rial‎appli‎c atio‎n s invol‎v e the model‎i ng of flow throu‎g h porou‎s media‎, such as filte‎rs, catal‎y st beds, and packi‎n g. This tutor‎i al illus‎t rate‎s how to set up and solve‎a probl‎e m invol‎v ing gas flow throu‎g h porou‎s media‎.The indus‎t rial‎probl‎e m solve‎d here invol‎v es gas flow throu‎g h a catal‎y tic conve‎r ter. Catal‎y tic conve‎r ters‎are commo‎n ly used to purif‎y emiss‎i ons from gasol‎i ne and diese‎l engin‎e s by conve‎r ting‎envir‎o nmen‎t ally‎hazar‎d ous exhau‎s t emiss‎i ons to accep‎t able‎subst‎a nces‎.Examp‎l es of such emiss‎i ons inclu‎d e carbo‎n monox‎i de (CO), nitro‎g en oxide‎s (NOx), and unbur‎n ed hydro‎c arbo‎n fuels‎. These‎exhau‎s t gas emiss‎i ons are force‎d throu‎g h a subst‎r ate, which‎is a ceram‎i c struc‎t ure coate‎d with a metal‎catal‎y st such as plati‎n um or palla‎d ium.The natur‎e of the exhau‎s t gas flow is a very impor‎t ant facto‎r in deter‎m inin‎g the perfo‎r manc‎e of the catal‎y tic conve‎r ter. Of parti‎c ular‎impor‎t ance‎is the press‎u re gradi‎e nt and veloc‎i ty distr‎i buti‎o n throu‎g h the subst‎r ate. Hence‎CFD analy‎s is is used to desig‎n effic‎i ent catal‎y tic conve‎r ters‎: by model‎i ng the exhau‎s t gas flow, the press‎u re drop and the unifo‎r mity‎of flow throu‎g h the subst‎r ate can be deter‎m ined‎. In this tutor‎i al, FLUEN‎T is used to model‎the flow of nitro‎g en gas throu‎g h a catal‎y tic conve‎r ter geome‎t ry, so that the flow field‎ struc‎t ure may be analy‎z ed.This tutor‎i al demon‎s trat‎e s how to do the follo‎w ing:_ Set up a porou‎s zone for the subst‎r ate with appro‎p riat‎e resis‎t ance‎s._ Calcu‎l ate a solut‎i on for gas flow throu‎g h the catal‎y tic conve‎r ter using‎the press‎u re based‎solve‎r. _ Plot press‎u re and veloc‎i ty distr‎i buti‎o n on speci‎f ied plane‎s of the geome‎t ry._ Deter‎m ine the press‎u re drop throu‎g h the subst‎r ate and the degre‎e of non-unifo‎r mity‎of flow throu‎g h cross‎secti‎o ns of the geome‎t ry using‎X-Y plots‎and numer‎i cal repor‎t s.Probl‎e m Descr‎i ptio‎nThe catal‎y tic conve‎r ter model‎e d here is shown‎in Figur‎e 7.1. The nitro‎g en flows‎in throu‎g h the inlet‎with a unifo‎r m veloc‎i ty of 22.6 m/s, passe‎s throu‎g h a ceram‎i c monol‎i th subst‎r ate with squar‎e shape‎d chann‎e ls, and then exits‎throu‎g h the outle‎t.While‎the flow in the inlet‎and outle‎t secti‎o ns is turbu‎l ent, the flow throu‎g h the subst‎r ate is lamin‎a r and is chara‎c teri‎z ed by inert‎i al and visco‎u s loss coeff‎i cien‎t s in the flow (X) direc‎t ion. The subst‎r ate is imper‎m eabl‎e in other‎direc‎t ions‎, which‎is model‎e d using‎loss coeff‎i cien‎ts whose‎value‎s are three‎order‎s of magni‎t ude highe‎r than in the X direc‎t ion.Setup‎and Solut‎i onStep 1: Grid1. Read the mesh file (catal‎y tic conve‎r ter.msh).File /Read /Case...2. Check‎the grid. Grid /Check‎FLUEN‎T will perfo‎r m vario‎u s check‎s on the mesh and repor‎t the progr‎e ss in the conso‎l e. Make sure that the minim‎u m volum‎e repor‎t ed is a posit‎i ve numbe‎r.3. Scale‎the grid.Grid! Scale‎...(a) Selec‎t mm from the Grid Was Creat‎e d In drop-down list.(b) Click‎the Chang‎e Lengt‎h Units‎butto‎n. All dimen‎s ions‎will now be shown‎in milli‎m eter‎s.(c) Click‎Scale‎and close‎the Scale‎Grid panel‎.4. Displ‎a y the mesh. Displ‎a y /Grid...(a) Make sure that inlet‎, outle‎t, subst‎r ate-wall, and wall are selec‎t ed in the Surfa‎c es selec‎t ion list.(b) Click‎Displ‎a y.(c) Rotat‎e the view and zoom in to get the displ‎a y shown‎in Figur‎e 7.2.(d) Close‎the Grid Displ‎a y panel‎.The hex mesh on the geome‎t ry conta‎i ns a total‎of 34,580 cells‎.Step 2: Model‎s1. Retai‎n the defau‎l t solve‎r setti‎n gs. Defin‎e /Model‎s /Solve‎r...2. Selec‎t the stand‎a rd k-ε turbu‎l ence‎model‎.Defin‎e/ Model‎s /Visco‎u s...Step 3: Mater‎i als1. Add nitro‎g en to the list of fluid‎ mater‎i als by copyi‎n g it from the Fluen‎t Datab‎a se for mater‎i als. Defin‎e /Mater‎i als...(a) Click‎the Fluen‎t Datab‎a se... butto‎n to open the Fluen‎t Datab‎a se Mater‎i als panel‎.i. Selec‎t nitro‎g en (n2) from the list of Fluen‎t Fluid‎Mater‎i als.ii. Click‎Copy to copy the infor‎m atio‎n for nitro‎g en to your list of fluid‎ mater‎i als. iii. Close‎the Fluen‎t Datab‎a se Mater‎i als panel‎.(b) Close‎the Mater‎i als panel‎.Step 4: Bound‎a ry Condi‎t ions‎.Defin‎e /Bound‎a ry Condi‎t ions‎...1. Set the bound‎a ry condi‎t ions‎for the fluid‎(fluid‎).(a) Selec‎t nitro‎g en from the Mater‎i al Name drop-down list.(b) Click‎OK to close‎the Fluid‎panel‎.2. Set the bound‎a ry condi‎t ions‎for the subst‎r ate (subst‎r ate).(a) Selec‎t nitro‎g en from the Mater‎i al Name drop-down list.(b) Enabl‎e the Porou‎s Zone optio‎n to activ‎a te the porou‎s zone model‎.(c) Enabl‎e the Lamin‎a r Zone optio‎n to solve‎the flow in the porou‎s zone witho‎u t turbu‎l ence‎.(d) Click‎the Porou‎s Zone tab.i. Make sure that the princ‎i pal direc‎t ion vecto‎r s are set as shown‎in Table‎7.1. Use the scrol‎l bar to acces‎s the field‎s that are not initi‎a lly visib‎l e in the panel‎.ii. Enter‎the value‎s in Table‎7.2 for the Visco‎u s Resis‎t ance‎and Inert‎i al Resis‎t ance‎. Scrol‎l down to acces‎s the field‎s that are not initi‎a lly visib‎l e in the panel‎.(e) Click‎OK to close‎the Fluid‎panel‎.3. Set the veloc‎i ty and turbu‎l ence‎bound‎a ry condi‎t ions‎at the inlet‎(inlet‎).(a) Enter‎22.6 m/s for the Veloc‎i ty Magni‎t ude.(b) Selec‎t Inten‎s ity and Hydra‎u lic Diame‎t er from the Speci‎f icat‎ion Metho‎d dropd‎o wn list in the Turbu‎l ence‎group‎box.(c) Retai‎n the defau‎l t value‎of 10% for the Turbu‎l ent Inten‎s ity.(d) Enter‎42 mm for the Hydra‎u lic Diame‎t er.(e) Click‎OK to close‎the Veloc‎i ty Inlet‎panel‎.4. Set the bound‎a ry condi‎t ions‎at the outle‎t (outle‎t).(a) Retai‎n the defau‎l t setti‎n g of 0 for Gauge‎Press‎u re.(b) Selec‎t Inten‎s ity and Hydra‎u lic Diame‎t er from the Speci‎f icat‎ion Metho‎d dropd‎o wn list in the Turbu‎l ence‎group‎box.(c) Enter‎5% for the Backf‎l ow Turbu‎l ent Inten‎s ity.(d) Enter‎42 mm for the Backf‎l ow Hydra‎u lic Diame‎t er.(e) Click‎OK to close‎the Press‎u re Outle‎t panel‎.5. Retai‎n the defau‎l t bound‎a ry condi‎t ions‎for the walls‎(subst‎r ate-wall and wall) and close‎the Bound‎a ry Condi‎t ions‎panel‎.Step 5: Solut‎i on1. Set the solut‎i on param‎e ters‎.Solve‎/Contr‎o ls /Solut‎i on...(a) Retai‎n the defau‎l t setti‎n gs for Under‎-Relax‎a tion‎Facto‎r s.(b) Selec‎t Secon‎d Order‎Upwin‎d from the Momen‎t um drop-down list in the Discr‎e tiza‎t ion group‎box.(c) Click‎OK to close‎the Solut‎i on Contr‎o ls panel‎.2. Enabl‎e the plott‎i ng of resid‎u als durin‎g the calcu‎l atio‎n. Solve‎/Monit‎o rs /Resid‎u al...(a) Enabl‎e Plot in the Optio‎n s group‎box.(b) Click‎OK to close‎the Resid‎u al Monit‎o rs panel‎.3. Enabl‎e the plott‎i ng of the mass flow rate at the outle‎t.Solve‎/ Monit‎o rs /Surfa‎c e...(a) Set the Surfa‎c e Monit‎o rs to 1.(b) Enabl‎e the Plot and Write‎optio‎n s for monit‎o r-1, and click‎the Defin‎e... butto‎n to open the Defin‎e Surfa‎c e Monit‎o r panel‎.i. Selec‎t Mass Flow Rate from the Repor‎t Type drop-down list.ii. Selec‎t outle‎t from the Surfa‎c es selec‎t ion list.iii. Click‎OK to close‎the Defin‎e Surfa‎c e Monit‎o rs panel‎.(c) Click‎OK to close‎the Surfa‎c e Monit‎o rs panel‎.4. Initi‎a lize‎the solut‎i on from the inlet‎.Solve‎/Initi‎a lize‎/Initi‎a lize‎...(a) Selec‎t inlet‎from the Compu‎t e From drop-down list.(b) Click‎Init and close‎the Solut‎i on Initi‎a liza‎t ion panel‎.5. Save the case file (catal‎y tic conve‎r ter.cas). File /Write‎/Case...6. Run the calcu‎l atio‎n by reque‎s ting‎100 itera‎t ions‎.Solve‎/Itera‎t e...(a) Enter‎100 for the Numbe‎r of Itera‎t ions‎.(b) Click‎Itera‎t e.The FLUEN‎T calcu‎l atio‎n will conve‎r ge in appro‎x imat‎e ly 70 itera‎t ions‎. By this point‎the mass flow rate monit‎o r has atten‎d ed out, as seen in Figur‎e 7.3.(c) Close‎the Itera‎t e panel‎.7. Save the case and data files‎(catal‎y tic conve‎r ter.cas and catal‎y tic conve‎r ter.dat).File /Write‎/Case & Data...Note: If you choos‎e a file name that alrea‎d y exist‎s in the curre‎n t folde‎r, FLUEN‎Twill promp‎t you for confi‎r mati‎o n to overw‎r ite the file.Step 6: Post-proce‎s sing‎1. Creat‎e a surfa‎c e passi‎n g throu‎g h the cente‎r line‎for post-proce‎s sing‎purpo‎s es.Surfa‎c e/Iso-Surfa‎c e...(a) Selec‎t Grid... and Y-Coord‎i nate‎from the Surfa‎c e of Const‎a nt drop-down lists‎.(b) Click‎Compu‎t e to calcu‎l ate the Min and Max value‎s.(c) Retai‎n the defau‎l t value‎of 0 for the Iso-Value‎s.(d) Enter‎y=0 for the New Surfa‎c e Name.(e) Click‎Creat‎e.2. Creat‎e cross‎-secti‎o nal surfa‎c es at locat‎i ons on eithe‎r side of the subst‎r ate, as well as at its cente‎r.Surfa‎c e /Iso-Surfa‎c e...(a) Selec‎t Grid... and X-Coord‎i nate‎from the Surfa‎c e of Const‎a nt drop-down lists‎.(b) Click‎Compu‎t e to calcu‎l ate the Min and Max value‎s.(c) Enter‎95 for Iso-Value‎s.(d) Enter‎x=95 for the New Surfa‎c e Name.(e) Click‎Creat‎e.(f) In a simil‎a r manne‎r, creat‎e surfa‎c es named‎x=130 and x=165 with Iso-Value‎s of 130 and 165, respe‎c tive‎l y. Close‎the Iso-Surfa‎c e panel‎after‎all the surfa‎c es have been creat‎e d.3. Creat‎e a line surfa‎c e for the cente‎r line‎of the porou‎s media‎.Surfa‎c e /Line/Rake...(a) Enter‎the coord‎i nate‎s of the line under‎End Point‎s, using‎the start‎i ng coord‎i nate‎of (95, 0, 0) and an endin‎g coord‎i nate‎of (165, 0, 0), as shown‎.(b) Enter‎porou‎s-cl for the New Surfa‎c e Name.(c) Click‎Creat‎e to creat‎e the surfa‎c e.(d) Close‎the Line/Rake Surfa‎c e panel‎.4. Displ‎a y the two wall zones‎(subst‎r ate-wall and wall). Displ‎a y /Grid...(a) Disab‎l e the Edges‎optio‎n.(b) Enabl‎e the Faces‎optio‎n.(c) Desel‎e ct inlet‎and outle‎t in the list under‎Surfa‎c es, and make sure that only subst‎r ate-wall and wall are selec‎t ed.(d) Click‎Displ‎a y and close‎the Grid Displ‎a y panel‎.(e) Rotat‎e the view and zoom so that the displ‎a y is simil‎a r to Figur‎e 7.2.5. Set the light‎i ng for the displ‎a y. Displ‎a y /Optio‎n s...(a) Enabl‎e the Light‎s On optio‎n in the Light‎i ng Attri‎b utes‎group‎box.(b) Retai‎n the defau‎l t selec‎t ion of Goura‎n d in the Light‎i ng drop-down list.(c) Click‎Apply‎and close‎the Displ‎a y Optio‎n s panel‎.6. Set the trans‎p aren‎c y param‎e ter for the wall zones‎(subst‎r ate-wall and wall).Displ‎a y/Scene‎...(a) Selec‎t subst‎r ate-wall and wall in the Names‎selec‎t ion list.(b) Click‎the Displ‎a y... butto‎n under‎Geome‎t ry Attri‎b utes‎to open the Displ‎a y Prope‎r ties‎panel‎.i. Set the Trans‎p aren‎c y slide‎r to 70.ii. Click‎Apply‎and close‎the Displ‎a y Prope‎r ties‎panel‎.(c) Click‎Apply‎and then close‎the Scene‎Descr‎i ptio‎n panel‎.7. Displ‎a y veloc‎i ty vecto‎r s on the y=0 surfa‎c e.Displ‎a y /Vecto‎r s...(a) Enabl‎e the Draw Grid optio‎n. The Grid Displ‎a y panel‎will open.i. Make sure that subst‎r ate-wall and wall are selec‎t ed in the list under‎Surfa‎c es.ii. Click‎Displ‎a y and close‎the Displ‎a y Grid panel‎.(b) Enter‎5 for the Scale‎.(c) Set Skip to 1.(d) Selec‎t y=0 from the Surfa‎c es selec‎t ion list.(e) Click‎Displ‎a y and close‎the Vecto‎r s panel‎.The flow patte‎r n shows‎that the flow enter‎s the catal‎y tic conve‎r ter as a jet, with recir‎c ulat‎i on on eithe‎r side of the jet. As it passe‎s throu‎g h the porou‎s subst‎r ate, it decel‎e rate‎s and strai‎g hten‎s out, and exhib‎i ts a more unifo‎r m veloc‎i ty distr‎i buti‎o n.This allow‎s the metal‎catal‎y st prese‎n t in the subst‎r ate to be more effec‎t ive.Figur‎e 7.4: Veloc‎i ty Vecto‎r s on the y=0 Plane‎8. Displ‎a y fille‎d conto‎u rs of stati‎c press‎u re on the y=0 plane‎.Displ‎a y /Conto‎u rs...(a) Enabl‎e the Fille‎d optio‎n.(b) Enabl‎e the Draw Grid optio‎n to open the Displ‎a y Grid panel‎.i. Make sure that subst‎r ate-wall and wall are selec‎t ed in the list under‎Surfa‎c es.ii. Click‎Displ‎a y and close‎the Displ‎a y Grid panel‎.(c) Make sure that Press‎u re... and Stati‎c Press‎u re are selec‎t ed from the Conto‎u rs of drop-down lists‎.(d) Selec‎t y=0 from the Surfa‎c es selec‎t ion list.(e) Click‎Displ‎a y and close‎the Conto‎u rs panel‎.Figur‎e 7.5: Conto‎u rs of the Stati‎c Press‎u re on the y=0 plane‎The press‎u re chang‎e s rapid‎l y in the middl‎e secti‎o n, where‎the fluid‎ veloc‎i ty chang‎e s as it passe‎s throu‎g h the porou‎s subst‎r ate. The press‎u re drop can be high, due to the inert‎i al and visco‎u s resis‎t ance‎of the porou‎s media‎. Deter‎m inin‎g this press‎u re drop is a goal of CFD analy‎s is. In the next step, you will learn‎how to plot the press‎u re drop along‎the cente‎r line‎of the subst‎r ate.9. Plot the stati‎c press‎u re acros‎s the line surfa‎c e porou‎s-cl.Plot /XY Plot...(a) Make sure that the Press‎u re... and Stati‎c Press‎u re are selec‎t ed from the Y Axis Funct‎i on drop-down lists‎.(b) Selec‎t porou‎s-cl from the Surfa‎c es selec‎t ion list.(c) Click‎Plot and close‎the Solut‎i on XY Plot panel‎.Figur‎e 7.6: Plot of the Stati‎c Press‎u re on the porou‎s-cl Line Surfa‎c eIn Figur‎e 7.6, the press‎u re drop acros‎s the porou‎s subst‎r ate can be seen to be rough‎l y 300 Pa.10. Displ‎a y fille‎d conto‎u rs of the veloc‎i ty in the X direc‎t ion on the x=95, x=130 and x=165 surfa‎c es.Displ‎a y /Conto‎u rs...(a) Disab‎l e the Globa‎l Range‎optio‎n.(b) Selec‎t Veloc‎i ty... and X Veloc‎i ty from the Conto‎u rs of drop-down lists‎.(c) Selec‎t x=130, x=165, and x=95 from the Surfa‎c es selec‎t ion list, and desel‎e ct y=0.(d) Click‎Displ‎a y and close‎the Conto‎u rs panel‎.The veloc‎i ty profi‎l e becom‎e s more unifo‎r m as the fluid‎ passe‎s throu‎g h the porou‎s media‎. The veloc‎i ty is very high at the cente‎r (the area in red) just befor‎e the nitro‎g en enter‎s the subst‎r ate and then decre‎a ses as it passe‎s throu‎g h and exits‎the subst‎r ate. The area in green‎, which‎corre‎s pond‎s to a moder‎a te veloc‎i ty, incre‎a ses in exten‎t.Figur‎e 7.7: Conto‎u rs of the X Veloc‎i ty on the x=95, x=130, and x=165 Surfa‎c es11. Use numer‎i cal repor‎t s to deter‎m ine the avera‎g e, minim‎u m, and maxim‎u m of the veloc‎i tydistr‎i buti‎o n befor‎e and after‎the porou‎s subst‎r ate.Repor‎t /Surfa‎c e Integ‎r als...(a) Selec‎t Mass-Weigh‎t ed Avera‎g e from the Repor‎t Type drop-down list.(b) Selec‎t Veloc‎i ty and X Veloc‎i ty from the Field‎Varia‎b le drop-down lists‎.(c) Selec‎t x=165 and x=95 from the Surfa‎c es selec‎t ion list.(d) Click‎Compu‎t e.(e) Selec‎t Facet‎Minim‎u m from the Repor‎t Type drop-down list and click‎Compu‎t e again‎.(f) Selec‎t Facet‎Maxim‎u m from the Repor‎t Type drop-down list and click‎Compu‎t e again‎.(g) Close‎the Surfa‎c e Integ‎r als panel‎.The numer‎i cal repor‎t of avera‎g e, maxim‎u m and minim‎u m veloc‎i ty can be seen in the main FLUEN‎T conso‎l e, as shown‎in the follo‎w ing examp‎l e:The sprea‎d betwe‎e n the avera‎g e, maxim‎u m, and minim‎u m value‎s for X veloc‎i ty gives‎the degre‎e to which‎the veloc‎i ty distr‎i buti‎o n is non-unifo‎r m. You can also use these‎numbe‎r s to calcu‎l ate the veloc‎i ty ratio‎(i.e., the maxim‎u m veloc‎i ty divid‎e d by the mean veloc‎i ty) and the space‎veloc‎i ty (i.e., the produ‎c t of the mean veloc‎i ty and the subst‎r ate lengt‎h).Custo‎m field‎ funct‎i ons and UDFs can be also used to calcu‎l ate more compl‎e x measu‎r es ofnon-unifo‎r mity‎, such as the stand‎a rd devia‎t ion and the gamma‎unifo‎r mity‎index‎.Summa‎r yIn this tutor‎i al, you learn‎e d how to set up and solve‎a probl‎e m invol‎v ing gas flow throu‎g h porou‎s media‎in FLUEN‎T. You also learn‎e d how to perfo‎r m appro‎p riat‎e post-proce‎s sing‎to inves‎t igat‎e the flow field‎, deter‎m ine the press‎u re drop acros‎s the porou‎s media‎and non-unifo‎r mity‎of the veloc‎i ty distr‎i buti‎o n as the fluid‎ goes throu‎g h the porou‎s media‎.Furth‎e r Impro‎v emen‎t sThis tutor‎i al guide‎s you throu‎g h the steps‎to reach‎an initi‎a l solut‎i on. You may be able to obtai‎n a more accur‎a te solut‎i on by using‎an appro‎p riat‎e highe‎r-order‎discr‎e tiza‎t ion schem‎e and by adapt‎i ng the grid. Grid adapt‎i on can also ensur‎e that the solut‎i on is indep‎e nden‎t of the grid. These‎steps‎are demon‎s trat‎e d in Tutor‎i al 1.。

多介质环境目标值-换算公式

多介质环境目标值-换算公式化学物质在没有环境空气质量标准和居住区大气环境质量标准情况下，推荐大家采用AMEG值，主要计算公式如下：美国环保局于1977年公布了该局工业环境实验室用模式推算出来的六百多中化学物质在各种环境介质（空气、水、土壤）中的限定值。

又于1980年对其进行了增补，并建议将其作为环境评价的依据值。

这些限定值被称为多介质环境目标值（Multimeedia Environmental Goal,MEG）。

所有目标值都是在最基本的毒性数据基础上，以统一模式推算的，系统性和可比性好。

因而，多介质环境目标值虽然不具法律效力，却可以作为环境评价的依据。

目前，它已在美国环境影响评价中广泛应用。

●以毒理学数据LD50为基础的计算公式为：AMEG=0.107×LD50/1000式中：AMEG－空气环境目标值(相当于居住区空气中日平均最高容许浓度，mg/m3) LD50－大鼠经口给毒的半数致死剂量以环氧乙烷为例，LD50--330mg/kg，计算得AMEG值= 0.04mg/m3，因此推荐居住区环境空气中环氧乙烷最高容许浓度为0.04 mg/m3（日平均值），根据《环境影响评价技术导则-大气环境》(HJ/T2.2-93)“8.1.2.5 如无法获得8.1.2.1中所述的监测资料，一次取样、日、月、季（或期）、年平均值可按1、0.33、0.20、0.14、0.12的比例关系换算”，则计算得相应1小时平均值为0.11 mg/m3。

●以阙限值为基础的计算公式为：AMEG＝阙限值/420式中：AMEG-空气环境目标值(相当于居住区空气中日平均最高容许浓度，mg/m3) 阙限值-美国政府工业卫生学家会议(ACGIH)制定的车间空气容许浓度，即每周工作5天，每天工作8小时条件下，成年工人可以耐受的化学物质在空气中的时间加权平均浓度，mg/m3●以健康影响为依据的空气介质排放环境目标值（DMEGAH）可按下式计算：DMEGAH (μg/m3) = 45× LD50式中：DMEGAH——允许排放浓度，LD50——化学物质的毒理数据，一般取大鼠经口给毒的LD50，若无此数据，可取与其接近的毒理学数据。

压力容器设计计算书(MMF+AC+MB+SF)

多介质过滤器
原始数据
Flow(m /h)
3
活性炭过滤器
原始数据
8.5 Flow(m /h)
3
10
MMF 桶体直径 7 过滤流速（m/h） 1243.73 计算桶体直径(mm) 1200.00 修正桶体直径(mm) 7.52 修正流速（m/h） MMF 桶体高度填充总高度(mm) 膨胀系数膨胀高度(mm) 修正膨胀高度(mm) 上水帽高度(mm) 下水帽高度(mm) 过滤器总高度(mm) MMF 反洗水量 LV(m/h) 反洗流量(m /h) 正洗流速(m/h) 正洗流量(m3/h) 反洗时间(min) 静置时间(min) 正洗时间(min) 反洗总时间(min) 反洗水量(m3) 正洗水量(m3) 总水量(m3)
3
15 14.25 10 10 10 10 10 30 2.37 1.67 4.04
1200 0.4 480 500 100 100 1900
1200 9.22 7 8.5 10 10 10 30 3.20 1.42 4.62
LV(m/h) 反洗流量(m /h) 正洗流速(m/h) 正洗流量(m3/h) 反洗时间(min) 静置时间(min) 正洗时间(min) 反洗总时间(min) 反洗水量(m3) 正洗水量(m3) 总水量(m3)
3
ACF 桶体直径 10 过滤流速（m/h） 1128.67 计算桶体直径(mm) 1100.00 修正桶体直径(mm) 10.53 修正流速（m/h） ACF 桶体高度填充总高度(mm) 膨胀系数膨胀高度(mm) 修正膨胀高度(mm) 上水帽高度(mm) 下水帽高度(mm) 过滤器总高度(mm) ACF 反洗水量

(完整word版)fluent中多孔介质设置问题和算例

经过痛苦的一段经历，终于将局部问题真相大白，为了使保位同仁不再经过我之痛苦，现在将本人多孔介质经验公布如下，希望各位能加精：1。

Gambit中划分网格之后，定义需要做为多孔介质的区域为fluid,与缺省的fluid分别开来，再定义其名称，我习惯将名称定义为porous;2。

在fluent中定义边界条件define-boundary condition-porous(刚定义的名称)，将其设置边界条件为fluid,点击set按钮即弹出与fluid边界条件一样的对话框，选中porous zone与laminar复选框,再点击porous zone标签即出现一个带有滚动条的界面；3。

porous zone设置方法：1）定义矢量：二维定义一个矢量，第二个矢量方向不用定义，是与第一个矢量方向正交的；三维定义二个矢量，第三个矢量方向不用定义，是与第一、二个矢量方向正交的；（如何知道矢量的方向：打开grid图，看看X,Y,Z的方向，如果是X向，矢量为1,0,0,同理Y向为0,1,0，Z向为0,0,1,如果所需要的方向与坐标轴正向相反，则定义矢量为负）圆锥坐标与球坐标请参考fluent帮助。

2）定义粘性阻力1/a与内部阻力C2：请参看本人上一篇博文“终于搞清fluent中多孔粘性阻力与内部阻力的计算方法”，此处不赘述；3）如果了定义粘性阻力1/a与内部阻力C2,就不用定义C1与C0，因为这是两种不同的定义方法，C1与C0只在幂率模型中出现，该处保持默认就行了；4）定义孔隙率porousity，默认值1表示全开放，此值按实验测值填写即可。

完了，其他设置与普通k-e或RSM相同。

总结一下，与君共享!Tutorial 7. Modeling Flow Through Porous MediaIntroductionMany industrial applications involve the modeling of flow through porous media, such as filters, catalyst beds, and packing. This tutorial illustrates how to set up and solve a problem involving gas flow through porous media.The industrial problem solved here involves gas flow through a catalytic converter. Catalytic converters are commonly used to purify emissions from gasoline and diesel engines by converting environmentally hazardous exhaust emissions to acceptable substances.Examples of such emissions include carbon monoxide (CO), nitrogen oxides (NOx), and unburned hydrocarbon fuels. These exhaust gas emissions are forced through a substrate, which is a ceramic structure coated with a metal catalyst such as platinum or palladium.The nature of the exhaust gas flow is a very important factor in determining the performance of the catalytic converter. Of particular importance is the pressure gradient and velocity distribution through the substrate. Hence CFD analysis is used to design efficient catalytic converters: by modeling the exhaust gas flow, the pressure drop and the uniformity of flow through the substrate can be determined. In this tutorial, FLUENT is used to model the flow of nitrogen gas through a catalytic converter geometry, so that the flow field structure may be analyzed.This tutorial demonstrates how to do the following:_ Set up a porous zone for the substrate with appropriate resistances._ Calculate a solution for gas flow through the catalytic converter using the pressure based solver. _ Plot pressure and velocity distribution on specified planes of the geometry._ Determine the pressure drop through the substrate and the degree of non-uniformity of flow through cross sections of the geometry using X-Y plots and numerical reports.Problem DescriptionThe catalytic converter modeled here is shown in Figure 7.1. The nitrogen flows in through the inlet with a uniform velocity of 22.6 m/s, passes through a ceramic monolith substrate with square shaped channels, and then exits through the outlet.While the flow in the inlet and outlet sections is turbulent, the flow through the substrate is laminar and is characterized by inertial and viscous loss coefficients in the flow (X) direction. The substrate is impermeable in other directions, which is modeled using loss coefficients whose values are three orders of magnitude higher than in the X direction.Setup and SolutionStep 1: Grid1. Read the mesh file (catalytic converter.msh).File /Read /Case...2. Check the grid. Grid /CheckFLUENT will perform various checks on the mesh and report the progress in the console. Make sure that the minimum volume reported is a positive number.3. Scale the grid.Grid! Scale...(a) Select mm from the Grid Was Created In drop-down list.(b) Click the Change Length Units button. All dimensions will now be shown in millimeters.(c) Click Scale and close the Scale Grid panel.4. Display the mesh. Display /Grid...(a) Make sure that inlet, outlet, substrate-wall, and wall are selected in the Surfaces selection list.(b) Click Display.(c) Rotate the view and zoom in to get the display shown in Figure 7.2.(d) Close the Grid Display panel.The hex mesh on the geometry contains a total of 34,580 cells.Step 2: Models1. Retain the default solver settings. Define /Models /Solver...2. Select the standard k-ε turbulence model. Define/ Models /Viscous...Step 3: Materials1. Add nitrogen to the list of fluid materials by copying it from the Fluent Database for materials.Define /Materials...(a) Click the Fluent Database... button to open the Fluent Database Materials panel.i. Select nitrogen (n2) from the list of Fluent Fluid Materials.ii. Click Copy to copy the information for nitrogen to your list of fluid materials. iii. Close the Fluent Database Materials panel.(b) Close the Materials panel.Step 4: Boundary Conditions. Define /Boundary Conditions...1. Set the boundary conditions for the fluid (fluid).(a) Select nitrogen from the Material Name drop-down list.(b) Click OK to close the Fluid panel.2. Set the boundary conditions for the substrate (substrate).(a) Select nitrogen from the Material Name drop-down list.(b) Enable the Porous Zone option to activate the porous zone model.(c) Enable the Laminar Zone option to solve the flow in the porous zone without turbulence.(d) Click the Porous Zone tab.i. Make sure that the principal direction vectors are set as shown in Table7.1. Use the scroll bar to access the fields that are not initially visible in the panel.ii. Enter the values in Table 7.2 for the Viscous Resistance and Inertial Resistance. Scroll down to access the fields that are not initially visible in the panel.(e) Click OK to close the Fluid panel.3. Set the velocity and turbulence boundary conditions at the inlet (inlet).(a) Enter 22.6 m/s for the Velocity Magnitude.(b) Select Intensity and Hydraulic Diameter from the Specification Method dropdown list in the Turbulence group box.(c) Retain the default value of 10% for the Turbulent Intensity.(d) Enter 42 mm for the Hydraulic Diameter.(e) Click OK to close the Velocity Inlet panel.4. Set the boundary conditions at the outlet (outlet).(a) Retain the default setting of 0 for Gauge Pressure.(b) Select Intensity and Hydraulic Diameter from the Specification Method dropdown list in the Turbulence group box.(c) Enter 5% for the Backflow Turbulent Intensity.(d) Enter 42 mm for the Backflow Hydraulic Diameter.(e) Click OK to close the Pressure Outlet panel.5. Retain the default boundary conditions for the walls (substrate-wall and wall) and close the Boundary Conditions panel.Step 5: Solution1. Set the solution parameters. Solve /Controls /Solution...(a) Retain the default settings for Under-Relaxation Factors.(b) Select Second Order Upwind from the Momentum drop-down list in the Discretization group box.(c) Click OK to close the Solution Controls panel.2. Enable the plotting of residuals during the calculation. Solve/Monitors /Residual...(a) Enable Plot in the Options group box.(b) Click OK to close the Residual Monitors panel.3. Enable the plotting of the mass flow rate at the outlet.Solve / Monitors /Surface...(a) Set the Surface Monitors to 1.(b) Enable the Plot and Write options for monitor-1, and click the Define... button to open the Define Surface Monitor panel.i. Select Mass Flow Rate from the Report Type drop-down list.ii. Select outlet from the Surfaces selection list.iii. Click OK to close the Define Surface Monitors panel.(c) Click OK to close the Surface Monitors panel.4. Initialize the solution from the inlet. Solve /Initialize /Initialize...(a) Select inlet from the Compute From drop-down list.(b) Click Init and close the Solution Initialization panel.5. Save the case file (catalytic converter.cas). File /Write /Case...6. Run the calculation by requesting 100 iterations. Solve /Iterate...(a) Enter 100 for the Number of Iterations.(b) Click Iterate.The FLUENT calculation will converge in approximately 70 iterations. By this point the mass flow rate monitor has attended out, as seen in Figure 7.3.(c) Close the Iterate panel.7. Save the case and data files (catalytic converter.cas and catalytic converter.dat).File /Write /Case & Data...Note: If you choose a file name that already exists in the current folder, FLUENTwill prompt you for confirmation to overwrite the file.Step 6: Post-processing1. Create a surface passing through the centerline for post-processing purposes.Surface/Iso-Surface...(a) Select Grid... and Y-Coordinate from the Surface of Constant drop-down lists.(b) Click Compute to calculate the Min and Max values.(c) Retain the default value of 0 for the Iso-Values.(d) Enter y=0 for the New Surface Name.(e) Click Create.2. Create cross-sectional surfaces at locations on either side of the substrate, as well as at its center.Surface /Iso-Surface...(a) Select Grid... and X-Coordinate from the Surface of Constant drop-down lists.(b) Click Compute to calculate the Min and Max values.(c) Enter 95 for Iso-Values.(d) Enter x=95 for the New Surface Name.(e) Click Create.(f) In a similar manner, create surfaces named x=130 and x=165 with Iso-Values of 130 and 165, respectively. Close the Iso-Surface panel after all the surfaces have been created.3. Create a line surface for the centerline of the porous media.Surface /Line/Rake...(a) Enter the coordinates of the line under End Points, using the starting coordinate of (95, 0, 0) and an ending coordinate of (165, 0, 0), as shown.(b) Enter porous-cl for the New Surface Name.(c) Click Create to create the surface.(d) Close the Line/Rake Surface panel.4. Display the two wall zones (substrate-wall and wall). Display /Grid...(a) Disable the Edges option.(b) Enable the Faces option.(c) Deselect inlet and outlet in the list under Surfaces, and make sure that only substrate-wall and wall are selected.(d) Click Display and close the Grid Display panel.(e) Rotate the view and zoom so that the display is similar to Figure 7.2.5. Set the lighting for the display. Display /Options...(a) Enable the Lights On option in the Lighting Attributes group box.(b) Retain the default selection of Gourand in the Lighting drop-down list.(c) Click Apply and close the Display Options panel.6. Set the transparency parameter for the wall zones (substrate-wall and wall).Display/Scene...(a) Select substrate-wall and wall in the Names selection list.(b) Click the Display... button under Geometry Attributes to open the Display Properties panel.i. Set the Transparency slider to 70.ii. Click Apply and close the Display Properties panel.(c) Click Apply and then close the Scene Description panel.7. Display velocity vectors on the y=0 surface.Display /Vectors...(a) Enable the Draw Grid option. The Grid Display panel will open.i. Make sure that substrate-wall and wall are selected in the list under Surfaces.ii. Click Display and close the Display Grid panel.(b) Enter 5 for the Scale.(c) Set Skip to 1.(d) Select y=0 from the Surfaces selection list.(e) Click Display and close the Vectors panel.The flow pattern shows that the flow enters the catalytic converter as a jet, with recirculation on either side of the jet. As it passes through the porous substrate, it decelerates and straightens out, and exhibits a more uniform velocity distribution.This allows the metal catalyst present in the substrate to be more effective.Figure 7.4: Velocity Vectors on the y=0 Plane8. Display filled contours of static pressure on the y=0 plane.Display /Contours...(a) Enable the Filled option.(b) Enable the Draw Grid option to open the Display Grid panel.i. Make sure that substrate-wall and wall are selected in the list under Surfaces.ii. Click Display and close the Display Grid panel.(c) Make sure that Pressure... and Static Pressure are selected from the Contours of drop-down lists.(d) Select y=0 from the Surfaces selection list.(e) Click Display and close the Contours panel.Figure 7.5: Contours of the Static Pressure on the y=0 planeThe pressure changes rapidly in the middle section, where the fluid velocity changes as it passes through the porous substrate. The pressure drop can be high, due to the inertial and viscous resistance of the porous media. Determining this pressure drop is a goal of CFD analysis. In the next step, you will learn how to plot the pressure drop along the centerline of the substrate.9. Plot the static pressure across the line surface porous-cl.Plot /XY Plot...(a) Make sure that the Pressure... and Static Pressure are selected from the Y Axis Function drop-down lists.(b) Select porous-cl from the Surfaces selection list.(c) Click Plot and close the Solution XY Plot panel.Figure 7.6: Plot of the Static Pressure on the porous-cl Line SurfaceIn Figure 7.6, the pressure drop across the porous substrate can be seen to be roughly 300 Pa.10. Display filled contours of the velocity in the X direction on the x=95, x=130 and x=165 surfaces.Display /Contours...(a) Disable the Global Range option.(b) Select Velocity... and X Velocity from the Contours of drop-down lists.(c) Select x=130, x=165, and x=95 from the Surfaces selection list, and deselect y=0.(d) Click Display and close the Contours panel.The velocity profile becomes more uniform as the fluid passes through the porous media. The velocity is very high at the center (the area in red) just before the nitrogen enters the substrate and then decreases as it passes through and exits the substrate. The area in green, which corresponds to a moderate velocity, increases in extent.Figure 7.7: Contours of the X Velocity on the x=95, x=130, and x=165 Surfaces11. Use numerical reports to determine the average, minimum, and maximum of the velocity distribution before and after the porous substrate.Report /Surface Integrals...(a) Select Mass-Weighted Average from the Report Type drop-down list.(b) Select Velocity and X Velocity from the Field Variable drop-down lists.(c) Select x=165 and x=95 from the Surfaces selection list.(d) Click Compute.(e) Select Facet Minimum from the Report Type drop-down list and click Compute again.(f) Select Facet Maximum from the Report Type drop-down list and click Compute again.(g) Close the Surface Integrals panel.The numerical report of average, maximum and minimum velocity can be seen in the main FLUENT console, as shown in the following example:The spread between the average, maximum, and minimum values for X velocity gives the degree to which the velocity distribution is non-uniform. You can also use these numbers to calculate the velocity ratio (i.e., the maximum velocity divided by the mean velocity) and the space velocity (i.e., the product of the mean velocity and the substrate length).Custom field functions and UDFs can be also used to calculate more complex measures ofnon-uniformity, such as the standard deviation and the gamma uniformity index.SummaryIn this tutorial, you learned how to set up and solve a problem involving gas flow through porous media in FLUENT. You also learned how to perform appropriate post-processing to investigate the flow field, determine the pressure drop across the porous media and non-uniformity of the velocity distribution as the fluid goes through the porous media.Further ImprovementsThis tutorial guides you through the steps to reach an initial solution. You may be able to obtain a more accurate solution by using an appropriate higher-order discretization scheme and by adapting the grid. Grid adaption can also ensure that the solution is independent of the grid. These steps aredemonstrated in Tutorial 1.。

fluent中多孔介质设置问题和算例

经过痛苦的一段经历，终于将局部问题真相大白，为了使保位同仁不再经过我之痛苦，现在将本人多孔介质经验公布如下，希望各位能加精：1。

Gambit 中划分网格之后，定义需要做为多孔介质的区域为fluid, 与缺省的fluid 分别开来，再定义其名称，我习惯将名称定义为porous;2。

在fluent 中定义边界条件define-boundary condition-porous（刚定义的名称），将其设置边界条件为fluid, 点击set 按钮即弹出与fluid 边界条件一样的对话框，选中porous zone 与laminar 复选框, 再点击porous zone 标签即出现一个带有滚动条的界面；3。

porous zone 设置方法：1）定义矢量：二维定义一个矢量，第二个矢量方向不用定义，是与第一个矢量方向正交的；三维定义二个矢量，第三个矢量方向不用定义，是与第一、二个矢量方向正交的；（如何知道矢量的方向：打开grid 图，看看X,Y,Z 的方向，如果是X 向，矢量为1,0,0, 同理Y 向为0,1,0 ，Z 向为0,0,1, 如果所需要的方向与坐标轴正向相反，则定义矢量为负）圆锥坐标与球坐标请参考fluent 帮助。

2）定义粘性阻力1/a 与内部阻力C2：请参看本人上一篇博文“ 终于搞清fluent 中多孔粘性阻力与内部阻力的计算方法”，此处不赘述；3）如果了定义粘性阻力1/a 与内部阻力C2,就不用定义C1 与C0，因为这是两种不同的定义方法，C1与C0 只在幂率模型中出现，该处保持默认就行了；4）定义孔隙率porousity ，默认值1 表示全开放，此值按实验测值填写即可。

完了，其他设置与普通k-e 或RSM相同。

总结一下，与君共享!Tutorial 7. Modeling Flow Through Porous MediaIntroductionMany industrial applications involve the modeling of flow through porous media, such as filters, catalyst beds, and packing. This tutorial illustrates how to set up and solve a problem involving gas flow through porous media.The industrial problem solved here involves gas flow through a catalytic converter. Catalytic converters are commonly used to purify emissions from gasoline and diesel engines by converting environmentally hazardous exhaust emissions to acceptable substances.Examples of such emissions include carbon monoxide (CO), nitrogen oxides (NOx), and unburned hydrocarbon fuels. These exhaust gas emissions are forced through a substrate, which is a ceramic structure coated with a metal catalyst such as platinum or palladium.The nature of the exhaust gas flow is a very important factor in determining the performance of the catalytic converter. Of particular importance is the pressure gradient and velocity distribution through the substrate. Hence CFD analysis is used to design efficient catalytic converters: by modeling the exhaust gas flow, the pressure drop and the uniformity of flow through the substrate can be determined. In this tutorial, FLUENT is used to model the flow of nitrogen gas through a catalytic converter geometry, so that the flow field structure may be analyzed.This tutorial demonstrates how to do the following:_ Set up a porous zone for the substrate with appropriate resistances._ Calculate a solution for gas flow through the catalytic converter using the pressure based solver._ Plot pressure and velocity distribution on specified planes of the geometry._ Determine the pressure drop through the substrate and the degree of non-uniformity of flow through cross sections of the geometry using X-Y plots and numerical reports.Problem DescriptionThe catalytic converter modeled here is shown in Figure 7.1. The nitrogen flows in through the inlet with a uniform velocity of 22.6 m/s, passes through a ceramic monolith substrate with square shaped channels, and then exits through the outlet.While the flow in the inlet and outlet sections is turbulent, the flow through the substrate is laminar and is characterized by inertial and viscous loss coefficients in the flow (X) direction. The substrate is impermeable in other directions, which is modeled using loss coefficients whose values are three orders of magnitude higher than in the X direction.Setup and SolutionStep 1: Grid1. Read the mesh file (catalytic converter.msh).File /Read /Case...2. Check the grid. Grid /CheckFLUENT will perform various checks on the mesh and report the progress in the console. Make sure that the minimum volume reported is a positive number.3. Scale the grid.Grid! Scale...(a) Select mm from the Grid Was Created In drop-down list.(b) Click the Change Length Units button. All dimensions will now be shown in millimeters.(c) Click Scale and close the Scale Grid panel.4. Display the mesh. Display /Grid...(a) Make sure that inlet, outlet, substrate-wall, and wall are selected in the Surfaces selection list.(b) Click Display.(c) Rotate the view and zoom in to get the display shown in Figure 7.2.(d) Close the Grid Display panel.The hex mesh on the geometry contains a total of 34,580 cells.Step 2: Models1. Retain the default solver settings. Define /Models /Solver...2. Select the standard k-ε turbulence model. Define/ Models /Viscous...Step 3: Materials1. Add nitrogen to the list of fluid materials by copying it from the Fluent Database for materials. Define /Materials...(a)Click the Fluent Database... button to open the Fluent Database Materials panel.(a) Select nitrogen from the Material Name drop-down list.(b)Click OK to close the Fluid panel.2. Set the boundary conditions for the substrate (substrate).i. Select nitrogen (n2) from the list of Fluent Fluid Materials.ii. Click Copy to copy the information for nitrogen to your list of fluid materials. iii. Close the Fluent Database Materials panel. (b) Close the Materials panel. Step 4: Boundary Conditions.1. Set the boundary conditions for the fluid (fluid).Define /Boundary Conditions...(a) Select nitrogen from the Material Name drop-down list.(b) Enable the Porous Zone option to activate the porous zone model.(c) Enable the Laminar Zone option to solve the flow in the porous zone without turbulence.(d) Click the Porous Zone tab.i. Make sure that the principal direction vectors are set as shown in Table7.1. Use the scroll bar to access the fields that are not initially visible in the panel.ii. Enter the values in Table 7.2 for the Viscous Resistance and Inertial Resistance. Scroll down to access the fields that are not initially visible in the panel.(e) Click OK to close the Fluid panel.3. Set the velocity and turbulence boundary conditions at the inlet (inlet).(a) Enter 22.6 m/s for the Velocity Magnitude.(b) Select Intensity and Hydraulic Diameter from the Specification Method dropdown list in the Turbulence group box.(c) Retain the default value of 10% for the Turbulent Intensity.(d) Enter 42 mm for the Hydraulic Diameter.(e) Click OK to close the Velocity Inlet panel.4. Set the boundary conditions at the outlet (outlet).(a) Retain the default setting of 0 for Gauge Pressure.(b) Select Intensity and Hydraulic Diameter from the Specification Method dropdown list in the Turbulence group box.(c) Enter 5% for the Backflow Turbulent Intensity.(d) Enter 42 mm for the Backflow Hydraulic Diameter.(e) Click OK to close the Pressure Outlet panel.5. Retain the default boundary conditions for the walls (substrate-wall and wall) and close the Boundary Conditions panel.Step 5: Solution1. Set the solution parameters. Solve /Controls /Solution...(a) Retain the default settings for Under-Relaxation Factors.(b) Select Second Order Upwind from the Momentum drop-down list in the Discretization group box.(c) Click OK to close the Solution Controls panel.2. Enable the plotting of residuals during the calculation. Solve/Monitors /Residual...(a)Enable Plot in the Options group box.(b)Click OK to close the Residual Monitors panel.3.Enable the plotting of the mass flow rate at the outlet.Solve / Monitors /Surface...(a) Set the Surface Monitors to 1.(b) Enable the Plot and Write options for monitor-1, and click the Define... button to open the Define Surface Monitor panel.i. Select Mass Flow Rate from the Report Type drop-down list.ii. Select outlet from the Surfaces selection list.iii. Click OK to close the Define Surface Monitors panel.(c) Click OK to close the Surface Monitors panel.4. Initialize the solution from the inlet. Solve /Initialize /Initialize...(a) Select inlet from the Compute From drop-down list.(b) Click Init and close the Solution Initialization panel.5. Save the case file (catalytic converter.cas). File /Write /Case...6. Run the calculation by requesting 100 iterations. Solve /Iterate...(a) Enter 100 for the Number of Iterations.(b) Click Iterate.The FLUENT calculation will converge in approximately 70 iterations. By this point the mass flow rate monitor has attended out, as seen in Figure 7.3.(c) Close the Iterate panel.7. Save the case and data files (catalytic converter.cas and catalytic converter.dat). File /Write /Case & Data...Note: If you choose a file name that already exists in the current folder, FLUENT will prompt you for confirmation to overwrite the file.Step 6: Post-processing1. Create a surface passing through the centerline for post-processing purposes.Surface/Iso-Surface...(a) Select Grid... and Y-Coordinate from the Surface of Constant drop-down lists.(b) Click Compute to calculate the Min and Max values.(c) Retain the default value of 0 for the Iso-Values.(d) Enter y=0 for the New Surface Name.(e) Click Create.2. Create cross-sectional surfaces at locations on either side of the substrate, as well as at its center.Surface /Iso-Surface...(a) Select Grid... and X-Coordinate from the Surface of Constant drop-down lists.(b) Click Compute to calculate the Min and Max values.(c) Enter 95 for Iso-Values.(d) Enter x=95 for the New Surface Name.(e) Click Create.(f) In a similar manner, create surfaces named x=130 and x=165 with Iso-Values of 130 and 165, respectively. Close the Iso-Surface panel after all the surfaces have been created.3. Create a line surface for the centerline of the porous media.Surface /Line/Rake...(a) Enter the coordinates of the line under End Points, using the starting coordinate of (95, 0, 0) and an ending coordinate of (165, 0, 0), as shown.(b) Enter porous-cl for the New Surface Name.(c) Click Create to create the surface.(d) Close the Line/Rake Surface panel.4. Display the two wall zones (substrate-wall and wall). Display /Grid...(a) Disable the Edges option.(b) Enable the Faces option.(c) Deselect inlet and outlet in the list under Surfaces, and make sure that only substrate-wall and wall are selected.(d) Click Display and close the Grid Display panel.(e) Rotate the view and zoom so that the display is similar to Figure 7.2.5. Set the lighting for the display. Display /Options...(a) Enable the Lights On option in the Lighting Attributes group box.(b) Retain the default selection of Gourand in the Lighting drop-down list.(c) Click Apply and close the Display Options panel.6. Set the transparency parameter for the wall zones (substrate-wall and wall). Display/Scene...(a) Select substrate-wall and wall in the Names selection list.(b) Click the Display... button under Geometry Attributes to open the Display Properties panel.i. Set the Transparency slider to 70.ii. Click Apply and close the Display Properties panel.(c) Click Apply and then close the Scene Description panel.7. Display velocity vectors on the y=0 surface.Display /Vectors...(a) Enable the Draw Grid option. The Grid Display panel will open.i. Make sure that substrate-wall and wall are selected in the list under Surfaces.ii. Click Display and close the Display Grid panel.(b) Enter 5 for the Scale.(c) Set Skip to 1.(d) Select y=0 from the Surfaces selection list.(e) Click Display and close the Vectors panel.The flow pattern shows that the flow enters the catalytic converter as a jet, with recirculation on either side of the jet. As it passes through the porous substrate, it decelerates and straightens out, and exhibits a more uniform velocity distribution.This allows the metal catalyst present in the substrate to be more effective.Figure 7.4: Velocity Vectors on the y=0 Plane8. Display filled contours of static pressure on the y=0 plane.Display /Contours...(a) Enable the Filled option.(b) Enable the Draw Grid option to open the Display Grid panel.i. Make sure that substrate-wall and wall are selected in the list under Surfaces.ii. Click Display and close the Display Grid panel.(c) Make sure that Pressure... and Static Pressure are selected from the Contours of drop-down lists.(d) Select y=0 from the Surfaces selection list.(e) Click Display and close the Contours panel.Figure 7.5: Contours of the Static Pressure on the y=0 planeThe pressure changes rapidly in the middle section, where the fluid velocity changes as it passes through the porous substrate. The pressure drop can be high, due to the inertial and viscous resistance of the porous media. Determining this pressure drop is a goal of CFD analysis. In the next step, you will learn how to plot the pressure drop along the centerline of the substrate.9. Plot the static pressure across the line surface porous-cl.Display /Contours...Plot /XY Plot...(a) Make sure that the Pressure... and Static Pressure are selected from the Y Axis Function drop-down lists.(b) Select porous-cl from the Surfaces selection list.(c)Click Plot and close the Solution XY Plot panel.(a) Disable the Global Range option.Figure 7.6: Plot of the Static Pressure on the porous-cl Line SurfaceIn Figure 7.6, the pressure drop across the porous substrate can be seen to be roughly 300 Pa.10. Display filled contours of the velocity in the X direction on the x=95, x=130 and x=165 surfaces.(b) Select Velocity... and X Velocity from the Contours of drop-down lists.(c) Select x=130, x=165, and x=95 from the Surfaces selection list, and deselect y=0.(d) Click Display and close the Contours panel.The velocity profile becomes more uniform as the fluid passes through the porous media. The velocity is very high at the center (the area in red) just before the nitrogen enters the substrate and then decreases as it passes through and exits the substrate. The area in green, which corresponds to a moderate velocity, increases in extent.Figure 7.7: Contours of the X Velocity on the x=95, x=130, and x=165 Surfaces 11. Use numerical reports to determine the average, minimum, and maximum of the velocity distribution before and after the porous substrate.Report /Surface Integrals...(a) Select Mass-Weighted Average from the Report Type drop-down list.(b) Select Velocity and X Velocity from the Field Variable drop-down lists.(c) Select x=165 and x=95 from the Surfaces selection list.(d) Click Compute.(e) Select Facet Minimum from the Report Type drop-down list and click Compute again.(f) Select Facet Maximum from the Report Type drop-down list and click Compute again.(g) Close the Surface Integrals panel.The numerical report of average, maximum and minimum velocity can be seen in the main FLUENT console, as shown in the following example:The spread between the average, maximum, and minimum values for X velocity gives the degree to which the velocity distribution is non-uniform. You can also use these numbers to calculate the velocity ratio (i.e., the maximum velocity divided by the mean velocity) and the space velocity (i.e., the product of the mean velocity and the substrate length).Custom field functions and UDFs can be also used to calculate more complex measures of non-uniformity, such as the standard deviation and the gamma uniformity index.SummaryIn this tutorial, you learned how to set up and solve a problem involving gas flow through porous media in FLUENT. You also learned how to perform appropriate post-processing to investigate the flow field, determine the pressure drop across the porous media and non-uniformity of the velocity distribution as the fluid goes through the porous media.Further ImprovementsThis tutorial guides you through the steps to reach an initial solution. You may be able to obtain a more accurate solution by using an appropriate higher-order discretization scheme and by adapting the grid. Grid adaption can also ensure that the solution is independent of the grid. These steps are demonstrated in Tutorial 1.。

多介质过滤器说明书

多介质过滤器使用说明书南京南自科林系统工程有限公司地址：南京浦口高新区星火路8号一、工艺原理：多介质过滤器为水处理系统的预处理设备，适用于浊度在1-10NTU的进水；目的除去水中的悬浮物、颗粒和胶体，降低进水的浊度和SDI值，满足除盐装置后续设备的进水要求；设备可以通过周期性的清洗来恢复它的截污能力。

二、技术参数：1.进水浊度： < 10 NTU2.出水浊度： < 1 NTU3.工作压力: < 0.6MPa4.工作温度: 5-50℃5.运行流速: 6-10m/h6.水反洗强度: 20-30m/h7.气擦洗强度: 15L/m2.s8.填料高度: 无烟煤400/石英砂8009.石英砂规格：0.5～1.2mm （不均匀系数＜2 ）无烟煤规格：0.8～1.8mm （不均匀系数＜1.7 ）10．承托层：（如设备要求）三、结构形式：设备由本体、布水装置、集水装置、外配管及仪表取样装置等组成。

进水装置为上进水、挡板布水，集水装置为多孔板滤水帽集水或穹形多孔板加承托层结构；设备的本体外部配管配带阀门并留有压力取样接口，便于用户现场安装和实现装置正常运行。

四. 设备的安装1）安装前检查土建基础是否按设计要求施工。

2）设备按设计图纸进行就位，调整支腿垫铁并检查进出口法兰的水平度和垂直度。

3）将设备和基础预埋铁板焊接固定，固定后再次校验进出口法兰的水平度和垂直度。

4）将设备本体配管按编号区分后依设计图纸进行组装，每段管道组装前应用干净抹布对内壁进行清洁工作，组装后应保持配管轴线横平竖直，阀门朝向合理（手动阀手柄朝前，气动阀启动头朝上）。

5）检查本体阀门开关灵活，有卡壳的情况及时整改。

6）设备本体配管完成后应对阀组进行必要的支撑工作等。

7）安装设备上配带的进出水压力表、取样阀等；进出水管道上如有流量探头座应用堵头堵住。

五、初次开车1）. 冲洗考虑到设备和管道连接时的电焊残渣、管道初次投用时的表面污物，设备初次投入运行时应进行冲洗。

多楔带传动设计计算

多楔带传动设计计算% 多楔带传动设计计算% 已知条件P=7.5; % 离心式鼓风机电动机功率(kW)n1=720; % 电动机转速（r/min）n2=450; % 电动机转速（r/min）a0=955; % 初定中心距（mm）% 1-选择多楔带型号Ka=input(' 查表12-10，选取工况系数 Ka = ');Pc=Ka*P;fprintf(' 计算功率 Pc = %3.4f kW \n',Pc);disp ' @@ 多楔带常用类型:PJ\PL\PM @@'DXDX=input(' 查图12-5，选取多楔带类型 DXDX = ','s');% 2-确定多楔带轮的有效直径i=n1/n2;fprintf(' 传动比 i = %3.4f \n',i);de1=input(' 查表12-11，确定主动多楔带轮有效直径(mm) de1 = '); switch DXDX % 根据多楔带型号选取多楔带轮直径增量 case 'PJ' Delta_e=1.2;case 'PL'Delta_e=3;case 'PM'Delta_e=4;endfprintf(' 多楔带轮直径增量(mm) Delta_e = %3.4f mm \n',Delta_e); epslion=input(' 确定多楔带传动的滑差率 epslion = ');de20=i*(de1+2*Delta_e)*(1-epslion)-2*Delta_e;fprintf(' 主动多楔带轮有效直径计算值de20 = %3.4f mm \n',de20); de2=input(' 查表12-11，确定从动多楔带轮有效直径(mm)de2 = '); % 3-确定多楔带的有效长度和中心距Ld0=2*a0+pi*(de1+de2)/2+(de2-de1)^2/(4*a0);fprintf(' 多楔带有效长度计算值 Ld0 = %3.4f mm \n',Ld0);Ld=input(' 查表12-12，确定多楔带有效长度(mm) Ld = ');Kl=input(' 查表12-12，确定多楔带带长修正系数 Kl = ');a=a0+(Ld-Ld0)/2;fprintf(' 多楔带传动中心距 a = %3.4f mm \n',a);if Ld>=1250 & Ld<1500delta_max=16;delta_min=22;elseif Ld>=1500 & Ld<1800delta_max=19;delta_min=22;elseif Ld>=1800 & Ld<2000delta_max=22;delta_min=24;elseif Ld>=2000 & Ld<2240delta_max=25;delta_min=24;elseif Ld>=2240 & Ld<2500delta_max=29;delta_min=25;elseif Ld>=2500 & Ld<3000delta_max=34;delta_min=27;elseif Ld>=3000 & Ld<4000delta_max=40;delta_min=29;endfprintf(' 查表12-13，中心距最小调整量 delta_min = %3.4f mm \n',delta_min);fprintf(' 查表12-13，中心距最大调整量 delta_max = %3.4f mm \n',delta_max);a_min=a-delta_min;a_max=a+delta_max;fprintf(' 多楔带中心距最小值 a_min = %3.4f mm \n',a_min);fprintf(' 多楔带中心距最大值 a_max = %3.4f mm \n',a_max);% 4-计算主动多楔带轮包角alpha=180-180*de1*(i-1)/pi/a;fprintf(' 主动多楔带轮包角 alp ha = %3.4f °\n',alpha);Kalpha=DXD_BJXS(alpha);fprintf(' * 表12-14，插值确定带轮包角修正系数Kalpha = %3.4f \n',Kalpha);% 5-确定带的楔数disp ' * 表12-15，插值确定多楔带基本额定功率'P0=DXD_JBEDGL(n1);fprintf(' 多楔带基本额定功率 P0 = %3.4f kW \n',P0);disp ' * 表12-16，插值确定多楔带传动功率增量'DP0=DXD_GLZL(n1);fprintf(' 多楔带传动功率增量 DP0 = %3.4f kW \n',DP0);zmin=Pc/((P0+DP0)*Kalpha*Kl);fprintf(' 带楔数的计算值 zmin = %3.4f \n',zmin);z=input(' 确定带的楔数 z = ');% 6-计算带速和压轴力v=pi*de1*n1/6e4;fprintf(' 多楔带运转速度 v = %3.4f m/s \n',v);F=1e3*Pc/v;fprintf(' 作用在轴上有效拉力 F = %3.4f N \n',F);Kz=DXD_XHXS(alpha);fprintf(' * 表12-17，插值确定多楔带楔合系数 Kz = %3.4f \n',Kz);FQ=Kz*F*sin(0.5*alpha*pi/180);fprintf(' 多楔带传动压轴力 FQ = %3.4f N \n',FQ);% 多楔带包角修正系数线性插值的函数文件(表12-14)function Kalpha=DXD_BJXS(alpha)x=[83 87 91 95 99 103 106 110 113 117 120 125 127 130 133 136 139 142 145 148 151 154 157 160 163 166 169 171 174 177 180];y=[0.64 0.66 0.68 0.70 0.72 0.73 0.75 0.76 0.77 0.79 0.80 0.810.83 0.84 0.850.86 0.87 0.88 0.89 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.970.98 0.991.00];Kalpha=interp1(x,y,alpha,'linear');% PL型多楔带基本额定功率的线性插值函数文件(表12-15)function P0=DXD_JBEDGL(n1)n1s=input(' 主动多楔带轮转速首值 n1s = ');n1w=input(' 主动多楔带轮转速尾值 n1w = ');P0s=input(' 对应主动多楔带轮有效直径的基本额定功率首值 P0s = ');P0w=input(' 对应主动多楔带轮有效直径的基本额定功率尾值P0w = '); P0=P0s+(n1-n1s)*(P0w-P0s)/(n1w-n1s);% PL型多楔带传动比引起的功率增量的线性插值函数文件(表12-16) function DP0=DXD_GLZL(n1)n1s=input(' 主动多楔带轮转速首值 n1s = ');n1w=input(' 主动多楔带轮转速尾值 n1w = ');DP0s=input(' 对应传动比的功率增量首值 DP0s = ');DP0w=input(' 对应传动比的功率增量尾值 DP0w = ');DP0=DP0s+(n1-n1s)*(DP0w-DP0s)/(n1w-n1s);% 多楔带楔合系数线性插值的函数文件(表12-17)function Kz=DXD_XHXS(alpha)al=[180 170 160 150 140 130 120];kz=[1.50 1.56 1.63 1.71 1.80 1.91 2.04];Kz=interp1(al,kz,alpha,'linear');计算结果：查表12-10，选取工况系数 Ka = 1.1计算功率 Pc = 8.2500 kW@@ 多楔带常用类型:PJ\PL\PM @@查图12-5，选取多楔带类型 DXDX = PL传动比 i = 1.6000查表12-11，确定主动多楔带轮有效直径(mm) de1 = 125多楔带轮直径增量(mm) Delta_e = 3.0000 mm确定多楔带传动的滑差率 epslion = 0.02主动多楔带轮有效直径计算值 de20 = 199.4080 mm查表12-11，确定从动多楔带轮有效直径(mm) de2 = 200多楔带有效长度计算值 Ld0 = 2421.9813 mm查表12-12，确定多楔带有效长度(mm) Ld = 2360查表12-12，确定多楔带带长修正系数 Kl = 0.96多楔带传动中心距 a = 924.0093 mm查表12-13，中心距最小调整量 delta_min = 25.0000 mm查表12-13，中心距最大调整量 delta_max = 29.0000 mm多楔带中心距最小值 a_min = 899.0093 mm多楔带中心距最大值 a_max = 953.0093 mm主动多楔带轮包角alpha = 175.3494 °* 表12-14，插值确定带轮包角修正系数 Kalpha = 0.9845* 表12-15，插值确定多楔带基本额定功率主动多楔带轮转速首值 n1s = 700主动多楔带轮转速尾值 n1w = 800对应主动多楔带轮有效直径的基本额定功率首值 P0s = 0.89对应主动多楔带轮有效直径的基本额定功率尾值 P0w = 0.98多楔带基本额定功率 P0 = 0.9080 kW* 表12-16，插值确定多楔带传动功率增量主动多楔带轮转速首值 n1s = 700主动多楔带轮转速尾值 n1w = 800对应传动比的功率增量首值 DP0s = 0.04对应传动比的功率增量尾值 DP0w = 0.05多楔带传动功率增量 DP0 = 0.0420 kW带楔数的计算值 zmin = 9.1885确定带的楔数 z = 10多楔带运转速度 v = 4.7124 m/s作用在轴上有效拉力 F = 1750.7044 N* 表12-17，插值确定多楔带楔合系数 Kz = 1.5279多楔带传动压轴力 FQ = 2672.7048 N。

FLUENT帮助里自带的多孔介质算例-经典资料

FLUENT帮助里自带的多孔介质算例-经典资料Tutorial 7. Modeling Flow Through Porous Media IntroductionMany industrial applications involve the modeling of ow through porous media, such as _lters, catalyst beds, and packing. This tutorial illustrates how to set up and solve a problem involving gas ow through porous media.The industrial problem solved here involves gas ow through a catalytic converter. Catalytic converters are commonly used to purify emissions from gasoline and diesel engines by converting environmentally hazardous exhaust emissions to acceptable substances.Examples of such emissions include carbon monoxide (CO), nitrogen oxides (NOx), and unburned hydrocarbon fuels. These exhaust gas emissions are forced through a substrate, which is a ceramic structure coated with a metal catalyst such as platinum or palladium.The nature of the exhaust gas ow is a very important factor in determining the performance of the catalytic converter. Of particular importance is the pressure gradient and velocity distribution through the substrate. Hence CFD analysis is used to designe_cient catalytic converters: by modeling the exhaust gas ow, the pressure drop andthe uniformity of ow through the substrate can be determined. In this tutorial, FLUENTis used to model the ow of nitrogen gas through a catalytic converter geometry, so that the ow _eld structure may be analyzed.This tutorial demonstrates how to do the following:_ Set up a porous zone for the substrate with appropriate resistances._ Calculate a solution for gas ow through the catalytic converter using the pressurebased solver._ Plot pressure and velocity distribution on speci_ed planes of the geometry._ Determine the pressure drop through the substrate and the degree of non-uniformityof ow through cross sections of the geometry using X-Y plots and numerical reports.许多工业应用都涉及通过多孔介质（如过滤器，催化剂床和填料）的流动模型。

多孔介质模型多孔介质,,技术总结

多孔介质模型多孔介质,-,技术总结12.4.3 可压缩流动的求解策略可压缩流动求解中速度、密度、压力和能量的高度耦合以及可能存在的激波导致求解过程不稳定。

有助于改善可压缩流动计算过程稳定性的方法有???(仅适用于基于压力求解器）以接近于滞止条件的流动参数进行初始化(即,压力很小但不为零,压力和温度分别等于进口总压和总温)。

在迭代过程的最初几十步不求解能量方程。

设置能量方程的亚松驰因子等于1,压力的亚松驰因子0.4,动量的亚松驰因子0.3。

求解过程稳定后再加入能量方程的求解,并将压力的亚松驰因子提高到0.7。

?设置合理的温度和压力限制值以避免求解过程发散。

?必要时,先以较低的进、出口边界压力比进行求解,然后再逐步升高压力比直到预定工况。

对于低Mach 数流动,也可以先求解不可压缩流动,然后以所得到的解作为可压缩流动的迭代初值。

某些情况下,也可以先求解无粘性流动作为迭代初值。

2.5 无粘性流动在高Re数流动中,惯性力相对于粘性力而言起支配作用,可忽略粘性的影响。

例如高速飞行器在空气动力学方案分析阶段可以采用无粘性流动计算初步确定外形,然后进行粘性计算,将流体粘性和湍流粘性对升力和阻力的影响计入。

无粘性流动计算的另一个用途是给复杂的流动提供好的迭代初值。

对于特别复杂的问题有时这是唯一能使求解过程进行下去的方法。

无粘性流动的计算求解 Euler 方程。

其中质量方程与粘性流动的相同:?粘性耗散项能量方程与粘性流动相比,式(2.34)~式(2.36)中符号的意义与粘性流动控制方程的相同见(2.1.1~2.1.3 节)。

2.6 多孔介质模型多孔介质(Porous Media)模型可用于模拟许多问题,包括流过填充床、滤纸、多孔板、布流器、管排等的流动。

多孔介质模型在流体区上定义(见17.2.1 节)。

此外,一个被称为多孔阶跃面(porous jump)的多孔介质模型的一维简化可用于模拟已知速度?压降特性的薄膜。

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反洗步骤：1、气洗，2、反洗，3、正洗
封头容积（m3）罐体截面积(m2) 单位 m3/h m3/h m3/h NTU ℃ NTU a m3/h m3/h m3/h Mpa min
m3/h Min m3/h Min mm mm mm mm m3 m3 m3 Mpa
1.0484 3.14 备注
最小量最大量
单纯气洗时间不要超过5min
调试时调整
调试时确定粒度2~4mm 粒度1~2mm 粒度0.5~1.2mm K80<2.0 粒度0.8~1.8mm K80<2.0 具体排水高度参考过滤器反排+排水+反排+正排反排+排水+反排+正排
作为反渗透进水预处理时
多介质过滤器计算书
项目名称项目编号罐体直径(mm) 2000 计算项目序号计算结果 1 产水量 1.1 最大产水量 44.0 1.2 最小产水量 18.8 1.3 设计流量 31.4 设计指标 2 2.1 进水浊度 <10 2.2 工作温度 5~50 2.3 出水浊度 0.5~1.0 2.4 工作压力 <0.6 4 压缩空气 4.1 压缩空气流量 113 4.2 压缩空气流量 170 4.3 压缩空气设计流量 136 0.1 4.4 压缩空气压力 5~10 4.5 气洗时间 5 反洗 5.1 反洗膨胀率 45-50% 反洗水流量 5.2 136 5.3 反洗时间 10 正洗 6 6.1 正洗流量 17 6.3 正洗时间 10 7 滤料装填高度 7.1 石英砂装填高度（2~4mm） 100 7.2 石英砂装填高度（1~2mm） 100 7.3 石英砂装填高度（0.5~1.2mm） 600 7.4 无烟煤装填高度（0.8~1.8mm） 400 2.9 8 气洗前放水 28.4 9 周期最大排水量周期最小排水量 28.4 10 运行终点判别 10.1 进出水压差 0.05 10.2 出水SDI <4