稳态热分析案例(ANSYS

1、本例题的主要部分为一个圆筒形罐，其上沿径向有一材料一样的接管（如图？所所示），罐内流动着450°F（232°C）的高温流体，接管内流动着100°F（38°C）的低温流体，两个流体区域由薄壁管隔离。罐的对流换热系数为250Btu/hr-ft2-oF（1420watts/m2-°K），接管的对流换热系数随管壁温度而变，它的热物理性能如表？所示。要求计算罐与接管的温度分布。表？温度70200300400500oF密度0.2850.2850.2850.2850.285lb/in3导热系数8.358.909.359.810.23oBtu/hr-ft-F比

2、热0.1130.1170.1190.1220.125Btu/lb-oF对流换热系数426405352275221Btu/hr-ft2-oF预处理Step1:确定分析标题起动ANSYS后，开始一个分析，需要输入一个标题，按下面方法进行操作：1. 选择UtilityMenuFileChangeTitle，弹出相应对话框2. 输入Steady-statethermalanalysisofpipejunction3. 点击OK。Step2:设置分析单位系统Youneedtospecifyunitsofmeasurementfortheanalysis.Forthispipejunctionexampl

3、e,measurementsusetheU.S.Customarysystemofunits(basedoninches).Tospecifythis,typethecommand/UNITS,BINintheANSYSInputwindowandpressENTER在分析之前，需要为分析系统设定单位系统，Step3:DefinetheElementTypeTheexampleanalysisusesathermalsolidelement.Todefineit,dothefollowing:1. ChooseMainMenuPreprocessorElementType>Add/Edi

4、t/DeleteTheElementTypesdialogboxappears.2. ClickonAdd.TheLibraryofElementTypesdialogboxappears.3. Inthelistontheleft,scrolldownandpick(highlight)"ThermalSolid."Inthelistontheright,pick"Brick20node90."4. ClickonOK.5. ClickonClosetoclosetheElementTypesdialogbox.Step4:DefineMaterial

5、PropertiesTodefinematerialpropertiesfortheanalysis,performthesesteps:1. ChooseMainMenu>PreprocessorMaterialProps>MaterialModels.TheDefineMaterialModelBehaviordialogboxappears.2. IntheMaterialModelsAvailablewindow,double-clickonthefollowingoptions:Thermal,Density.Adialogboxappears.3. Enter.285f

6、orDENS(Density),andclickonOK.MaterialModelNumber1appearsintheMaterialModelsDefinedwindowontheleft.4. IntheMaterialModelsAvailablewindow,double-clickonthefollowingoptions:Conductivity,Isotropic.Adialogboxappears.5. ClickontheAddTemperaturebuttonfourtimes.Fourcolumnsareadded.6. IntheT1throughT5fields,

7、enterthefollowingtemperaturevalues:70,200,300,400,and500.Selecttherowoftemperaturesbydraggingthecursoracrossthetextfields.ThencopythetemperaturesbypressingCtrl-c.7. IntheKXX(ThermalConductivity)fields,enterthefollowingvalues,inorder,foreachofthetemperatures,thenclickonOK.Notethattokeeptheunitsconsis

8、tent,eachofthegivenvaluesofKXXmustbedividedby12.YoucanjustinputthefractionsandhaveANSYSperformthecalculations.8.35/128.90/129.35/129.80/128.10.23/12IntheMaterialModelsAvailablewindow,double-clickondialogboxappears.ClickontheAddTemperaturebuttonfourtimes.Fourcolumnsareadded.10. Withthecursorpositione

9、dintheT1field,pastethefivetemperaturesbypressingCtrl-v.11. IntheC(SpecificHeat)fields,enterthefollowingvalues,inorder,foreachofthetemperatures,thenclickonOK.12512. ChoosemenupathMaterial>NewModel,thenenter2forthenewMaterialID.ClickonOK.MaterialModelNumber2appearsintheMaterialModelsDefinedwindowon

10、theleft.13. IntheMaterialModelsAvailablewindow,double-clickonConvectionorFilmCoef.Adialogboxappears.14. ClickontheAddTemperaturebuttonfourtimes.Fourcolumnsareadded.15. WiththecursorpositionedintheT1field,pastethefivetemperaturesbypressingCtrl-v.16. IntheHF(FilmCoefficient)fields,enterthefollowingval

11、ues,inorder,foreachofthetemperatures.Tokeeptheunitsconsistent,eachvalueofHFmustbedividedby144.Asinstep7,youcaninputthedataasfractionsandletANSYSperformthecalculations.426/144405/144352/144275/144221/144ClickontheGraphbuttontoviewagraphofFilmCoefficientsvs.temperature,thenclickonOK.17. ChoosemenupathMaterial>ExittoremovetheDefineMaterialModelBehaviordialogbox.18. ClickonSAVE_DBontheANSYSToolbar.Step5:DefineParametersforModelingChooseUtilityMenu>ParametersScalarParameters.TheScalarParameterswindowappears.1. Inthewindow'sSelectionfield,en