2022年ANSYS热分析指南[收 .pdf

ANSYS Thermal AnalysisGuideANSYS Release 10.0002184August 2005ANSYS, Inc. andANSYS Europe,Ltd. are ULregistered ISO9001:2000Companies.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 1 页，共 49 页 - - - - - - - - - ANSYS Thermal Analysis GuideANSYS Release 10.0ANSYS, Inc.Southpointe275 Technology DriveCanonsburg, PA http:/(T) 724-746-3304(F) 724-514-9494名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 2 页，共 49 页 - - - - - - - - - Copyright and Trademark Information? 2005 SAS IP, Inc. All rights reserved. Unauthorized use, distribution or duplication is prohibited.ANSYS, ANSYS Workbench, CFX, AUTODYN, and any and all ANSYS, Inc. product and service names are registered trademarks or trademarks of ANSYS, Inc.or its subsidiaries located in the United States or other countries. ICEM CFD is a trademark licensed by ANSYS, Inc. All other trademarks or registeredtrademarks are the property of their respective owners.Disclaimer NoticeTHIS ANSYS SOFTWARE PRODUCT AND PROGRAM DOCUMENTATION INCLUDE TRADE SECRETS AND ARE CONFIDENTIAL AND PROPRIETARY PRODUCTSOF ANSYS, INC., ITS SUBSIDIARIES, OR LICENSORS. The software products and documentation are furnished by ANSYS, Inc., its subsidiaries, or affiliatesunder a software license agreement that contains provisions concerning non-disclosure, copying, length and nature of use, compliance with exportinglaws, warranties, disclaimers, limitations of liability, and remedies, and other provisions. 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If you are unable to access the third-party legal notices, please contact ANSYS, Inc.Published in the U.S.A.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 3 页，共 49 页 - - - - - - - - - Table of Contents1. Analyzing Thermal Phenomena . 1 11.1. How ANSYS Treats Thermal Modeling . 1 11.1.1. Convection . 1 11.1.2. Radiation . 1 11.1.3. Special Effects . 1 21.2. Types of Thermal Analysis . 1 21.3. Coupled-Field Analyses . 121.4. About GUI Paths and Command Syntax . 122. Steady-State Thermal Analysis . 2 12.1. Available Elements for Thermal Analysis . 2 12.2. Commands Used in Thermal Analyses . 2 42.3. Tasks in a Thermal Analysis . 2 42.4. Building the Model . 2 42.4.1. Creating Model Geometry . 2 42.5. Applying Loads and Obtaining the Solution . 2 52.5.1. Defining the Analysis Type . 2 52.5.2. Applying Loads . 2 52.5.2.1. Constant Temperatures (TEMP) . 252.5.2.2. Heat Flow Rate (HEAT) . 2 62.5.2.3. Convections (CONV) . 2 62.5.2.4. Heat Fluxes (HFLUX) . 2 62.5.2.5. Heat Generation Rates (HGEN) . 2 62.5.3. Using Table and Function Boundary Conditions . 272.5.4. Specifying Load Step Options . 282.5.5. General Options . 2 92.5.6. Nonlinear Options . 2 102.5.6.1. Tracking Convergence Graphically . 2 112.5.7. Output Controls . 2 112.5.8. Defining Analysis Options . 2 122.5.9. Saving the Model . 2 132.5.10. Solving the Model . 2 132.6. Reviewing Analysis Results . 2 132.6.1. Primary data . 2 132.6.2. Derived data . 2 132.6.3. Reading In Results . 2 142.6.4. Reviewing Results . 2 142.7. Example of a Steady-State Thermal Analysis (Command or Batch Method) . 2 152.7.1. The Example Described . 2 152.7.2. The Analysis Approach . 2 162.7.3. Commands for Building and Solving the Model . 2 172.8. Doing a Steady-State Thermal Analysis (GUI Method) . 2 182.9. Doing a Thermal Analysis Using Tabular Boundary Conditions . 2 262.9.1. Running the Sample Problem via Commands . 2 262.9.2. Running the Sample Problem Interactively . 2 272.10. Where to Find Other Examples of Thermal Analysis . 2303. Transient Thermal Analysis . 3 13.1. Elements and Commands Used in Transient Thermal Analysis . 3 23.2. Tasks in a Transient Thermal Analysis . 3 23.3. Building the Model . 3 23.4. Applying Loads and Obtaining a Solution . 32ANSYS Thermal Analysis Guide . ANSYS Release 10.0 . 002184 . ? SAS IP, Inc.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 4 页，共 49 页 - - - - - - - - - 3.4.1. Defining the Analysis Type . 3 23.4.2. Establishing Initial Conditions for Your Analysis . 3 33.4.2.1. Specifying a Uniform Temperature . 3 33.4.2.2. Specifying a Non-Uniform Starting Temperature . 3 33.4.3. Specifying Load Step Options . 343.4.3.1. Defining Time-stepping Strategy . 3 43.4.3.2. General Options . 3 63.4.4. Nonlinear Options . 383.4.5. Output Controls . 3 103.5. Saving the Model . 3 113.5.1. Solving the Model . 3 113.6. Reviewing Analysis Results . 3 113.6.1. How to Review Results . 3 123.6.2. Reviewing Results with the General Postprocessor . 3 123.6.3. Reviewing Results with the Time History Postprocessor . 3123.7. Reviewing Results as Graphics or Tables . 3 133.7.1. Reviewing Contour Displays . 3 133.7.2. Reviewing Vector Displays . 3 133.7.3. Reviewing Table Listings . 3 133.8. Phase Change . 3 133.9. Example of a Transient Thermal Analysis . 3 143.9.1. The Example Described . 3 143.9.2. Example Material Property Values . 3153.9.3. Example of a Transient Thermal Analysis (GUI Method) . 3 163.9.4. Commands for Building and Solving the Model . 3 163.10. Where to Find Other Examples of Transient Thermal Analysis . 3174. Radiation . 4 14.1. Analyzing Radiation Problems . 414.2. Definitions . 414.3. Using LINK31, the Radiation Link Element . 4 24.4. Using the Surface Effect Elements . 4 24.5. Using the AUX12 Radiation Matrix Method . 4 34.5.1. Procedure . 4 34.5.1.1. Defining the Radiating Surfaces . 4 34.5.1.2. Generating the AUX12 Radiation Matrix . 4 54.5.1.3. Using the AUX12 Radiation Matrix in the Thermal Analysis . 4 64.5.2. Recommendations for Using Space Nodes . 4 74.5.2.1. Considerations for the Non-hidden Method . 4 74.5.2.2. Considerations for the Hidden Method . 4 74.5.3. General Guidelines for the AUX12 Radiation Matrix Method . 4 84.6. Using the Radiosity Solver Method . 4 94.6.1. Procedure . 4 94.6.1.1. Defining the Radiating Surfaces . 4 94.6.1.2. Defining Solution Options . 4 104.6.1.3. Defining View Factor Options . 4 114.6.1.4. Calculating and Querying View Factors . 4 124.6.1.5. Defining Load Options . 4124.6.2. Further Options for Static Analysis . 4 134.7. Advanced Radiosity Options . 4 134.8. Example of a 2-D Radiation Analysis Using the Radiosity Method (Command Method) . 4 174.8.1. The Example Described . 4 174.8.2. Commands for Building and Solving the Model . 4 18ANSYS Thermal Analysis Guide . ANSYS Release 10.0 . 002184 . ? SAS IP, Inc.viANSYS Thermal Analysis Guide名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 5 页，共 49 页 - - - - - - - - - 4.9. Example of a 2-D Radiation Analysis Using the Radiosity Method with Decimation and Symmetry(Command Method) . 4 184.9.1. The Example Described . 4 184.9.2. Commands for Building and Solving the Model . 4 19Index . Index 1List of Figures2.1. Convergence Norms . 2 112.2. Contour Results Plot . 2 142.3. Vector Display . 2 152.4. Pipe-Tank Junction Model . 2 163.1. Examples of Load vs. Time Curves . 3 13.2. Sample Enthalpy vs. Temperature Curve . 3144.1. Radiating Surfaces for 3-D and 2-D Models . 4 34.2. Superimposing Elements on Radiating Surfaces . 4 44.3. Orienting the Superimposed Elements . 4 54.4. Decimation . 4144.5. Planar Reflection . 4 154.6. Cyclic Repetition (Two Repetitions Shown) . 4 154.7. Multiple RSYMM Commands . 4 164.8. Annulus . 4 174.9. Problem Geometry . 4 19List of Tables2.1. 2-D Solid Elements . 222.2. 3-D Solid Elements . 222.3. Radiation Link Elements . 2 22.4. Conducting Bar Elements . 222.5. Convection Link Elements . 2 22.6. Shell Elements . 2 22.7. Coupled-Field Elements . 2 22.8. Specialty Elements . 232.9. Thermal Analysis Load Types . 2 62.10. Load Commands for a Thermal Analysis . 2 72.11. Boundary Condition Type and Corresponding Primary Variable . 2 72.12. Specifying Load Step Options . 2 82.13. Material Properties for the Sample Analysis . 2 16ANSYS Thermal Analysis GuideviiANSYS Thermal Analysis Guide . ANSYS Release 10.0 . 002184 . ? SAS IP, Inc.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 6 页，共 49 页 - - - - - - - - - viii名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 7 页，共 49 页 - - - - - - - - - Chapter 1: Analyzing Thermal PhenomenaA thermal analysis calculates the temperature distribution and related thermal quantities in a system or component.Typical thermal quantities of interest are:?The temperature distributions?The amount of heat lost or gained?Thermal gradients?Thermal fluxes.Thermal simulations play an important role in the design of many engineering applications, including internalcombustion engines, turbines, heat exchangers, piping systems, and electronic components. In many cases,engineers follow a thermal analysis with a stress analysis to calculate thermal stresses (that is, stresses caused bythermal expansions or contractions).The following thermal analysis topics are available:1.1. How ANSYS Treats Thermal Modeling1.2. Types of Thermal Analysis1.3. Coupled-Field Analyses1.4. About GUI Paths and Command Syntax1.1. How ANSYS Treats Thermal ModelingOnly the ANSYS Multiphysics, ANSYS Mechanical, ANSYS Professional, and ANSYS FLOTRAN programs supportthermal analyses.The basis for thermal analysis in ANSYS is a heat balance equation obtained from the principle of conservationof energy. (For details, consult the ANSYS, Inc. Theory Reference.) The finite element solution you perform viaANSYS calculates nodal temperatures, then uses the nodal temperatures to obtain other thermal quantities.The ANSYS program handles all three primary modes of heat transfer: conduction, convection, and radiation.1.1.1. ConvectionYou specify convection as a surface load on conducting solid elements or shell elements. You specify the convec-tion film coefficient and the bulk fluid temperature at a surface; ANSYS then calculates the appropriate heattransfer across that surface. If the film coefficient depends upon temperature, you specify a table of temperaturesalong with the corresponding values of film coefficient at each temperature.For use in finite element models with conducting bar elements (which do not allow a convection surface load),or in cases where the bulk fluid temperature is not known in advance, ANSYS offers a convection element namedLINK34. In addition, you can use the FLOTRAN CFD elements to simulate details of the convection process, suchas fluid velocities, local values of film coefficient and heat flux, and temperature distributions in both fluid andsolid regions.1.1.2. RadiationANSYS can solve radiation problems, which are nonlinear, in four ways:?By using the radiation link element, LINK31ANSYS Thermal Analysis Guide . ANSYS Release 10.0 . 002184 . ? SAS IP, Inc.名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 8 页，共 49 页 - - - - - - - - - ?By using surface effect elements with the radiation option (SURF151 in 2-D modeling or SURF152 in 3-Dmodeling)?By generating a radiation matrix in AUX12 and using it as a superelement in a thermal analysis.?By using the Radiosity Solver method.For detailed information on these methods, see Chapter 4, “Radiation”.1.1.3. Special EffectsIn addition to the three modes of heat transfer, you can account for special effects such as change of phase(melting or freezing) and internal heat generation (due to Joule heating, for example). For instance, you can usethe thermal mass element MASS71 to specify temperature-dependent heat generation rates.1.2. Types of Thermal AnalysisANSYS supports two types of thermal analysis:1.A steady-state thermal analysis determines the temperature distribution and other thermal quantitiesunder steady-state loading conditions. A steady-state loading condition is a situation where heat storageeffects varying over a period of time can be ignored.2.A transient thermal analysis determines the temperature distribution and other thermal quantities underconditions that vary over a period of time.1.3. Coupled-Field AnalysesSome types of coupled-field analyses, such as thermal-structural and magnetic-thermal analyses, can representthermal effects coupled with other phenomena. A coupled-field analysis can use matrix-coupled ANSYS elements,or sequential load-vector coupling between separate simulations of each phenomenon. For more informationon coupled-field analysis, see the ANSYS Coupled-Field Analysis Guide.1.4. About GUI Paths and Command SyntaxThroughout this document, you will see references to ANSYS commands and their equivalent GUI paths. Suchreferences use only the command name, because you do not always need to specify all of a commands arguments,and specific combinations of command arguments perform different functions. For complete syntax descriptionsof ANSYS commands, consult the ANSYS Commands Reference.The GUI paths shown are as complete as possible. In many cases, choosing the GUI path as shown will performthe function you want. In other cases, choosing the GUI path given in this document takes you to a menu ordialog box; from there, you must choose additional options that are appropriate for the specific task being per-formed.For all types of analyses described in this guide, specify the material you will be simulating using an intuitivematerial model interface. This interface uses a hierarchical tree structure of material categories, which is intendedto assist you in choosing the appropriate model for your analysis. See Section 1.1.4.4: Material Model Interfacein the ANSYS Basic Analysis Guide for details on the material model interface.ANSYS Thermal Analysis Guide . ANSYS Release 10.0 . 002184 . ? SAS IP, Inc.12Chapter 1: Analyzing Thermal Phenomena名师资料总结 - - -精品资料欢迎下载 - - - - - - - - - - - - - - - - - - 名师精心整理 - - - - - - - 第 9 页，共 49 页 - - - - - - - - - Chapter 2: Steady-State Thermal AnalysisThe ANSYS Multiphysics, ANSYS Mechanical, ANSYS FLOTRAN, and ANSYS Professional products support steady-state thermal analysis. A steady-state thermal analysis calculates the effects of steady thermal loads on a systemor component. Engineer/analysts often perform a steady-state analysis before doing a transient thermal analysis,to help establish initial conditions. A steady-state analysis also