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General thermal modeling
Contains general thermal solver knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
How to verify if thermal couplings are correctly defined?
This article provides a checklist to verify if the thermal coupling is correctly defined.

Knowledge base articles
- Knowledge base articles
  This knowledge base provides concise and informative articles focused on thermal, multiphysics, spacecraft application, and turbomachinery topics. Each article provides you with step-by-step guidance, best practices, and tips to help you handle complex processes and use key features effectively.
- General thermal modeling
  Contains general thermal solver knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
  - Troubleshooting thermal convergence issues and invalid temperature distribution
    This article describes the various causes of thermal solver convergence issues in simulation models, such as warning 6209 and situations where the conjugate solver fails to converge, or an invalid temperature distribution is detected. It provides detailed methods for diagnosing and resolving these issues.
  - Resolving warning 4410: Troubleshooting iterative heat flux convergence issues
    The article addresses Warning 4410, which occurs when the iterative heat flux calculation method fails to converge in thermal simulations, and provides a guide for identifying and resolving the underlying issues.
  - Resolving warning 4903: Interpolation is truncated for table
    This article addresses Warning 4903, a common issue encountered by users, and explores its meaning, causes, and practical steps to resolve it.
  - Resolving the "Not enough space for matrix" error message
    This article explains the error message related to insufficient space for the matrix and provides possible solutions.
  - How to define a thermostat based on a temperature difference between two elements?
    This article provides two methods for defining a thermostat based on a temperature difference between two elements.
  - How to use an average surface temperature as an input in expressions?
    To use the temperature of a solid as an input in expressions, you can use a function of the temperature at a specified point, TEMP(“point name”). However, Simcenter 3D does not have a specific function of the temperature on the surface to use in expressions. This article provides three alternative methods for using average surface temperature in expressions.
  - How to create a large assembly from smaller sub-assemblies?
    This article details the process of assembling a large structure from smaller sub-assemblies, enabling different groups to collaborate on different models before combining them into a single, unified assembly.
  - Thermal coupling methods
    This article explains coupling methods that the thermal solver supports.
  - Thermal coupling types
    The type of thermal coupling you define is determined by the geometry of the source and target regions you specify, as well as the type of heat transfer such as conduction, convection, and radiation. This article explains the different types of thermal coupling and provides guidance on where each type should be used.
  - How to create a thermal coupling between 2D and 3D geometry?
    This article explains how to set up thermal coupling between 2D-axisymmetric and 3D geometry.
  - How to verify if thermal couplings are correctly defined?
    This article provides a checklist to verify if the thermal coupling is correctly defined.
  - How to check connections in thermal coupling?
    This article shows how to visualize thermal connections before and after solving the model.
  - Simcenter 3D - Overview of thermal solver files and how to use them
    This article provides an overview of the thermal solver files and explains how to use them.
  - How to create a temperature difference plot to compare results?
    This article explains how to create a temperature difference plot using a formula field to compare results.
  - Understanding the preconditioned conjugate gradient solver and convergence checks in temperature calculation
    This article explains the preconditioned conjugate gradient solver, which is used by the thermal solver, preconditioning techniques, convergence criteria, and memory management strategies to enhance convergence speed and numerical stability of your thermal simulations.
  - How to write a thermal plugin in Simcenter 3D
    This article explains what a thermal plugin is, the benefits of using it, and how to create one.
- Space Systems Thermal
  Contains Spase Systems Thermal knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
- Multiphysics
  Contains multiphysics knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.

How to verify if thermal couplings are correctly defined?

This article provides a checklist to verify if the thermal coupling is correctly defined.

Details

Use the following check list to verify if thermal couplings are correctly defined:

Investigate if the primary and secondary elements are correctly connected thermally using the Thermal Connection result sets.
Run conduction only simulation:
- Remove all convective and radiative boundary conditions and loads, while leaving thermal contacts and joints in the model.
- Apply constraints at either end of the model to verify that thermal contacts are properly modeled. This can also serve as a check for specific heat in transient runs.
Check warning messages.
Use the Report command to investigate heat flow between components in the assembly, as well as from each component to the environment. This helps identify areas with significant heat accumulation and highlights where thermal tapes or thermal standoffs could be most beneficial in the design. The data from reports is generated in both .html and .csv formats.
Verify and determine individual conductances of elements in a thermal coupling by inspecting scratch files. Use the FILES MODLCF, VUFF, MODLF IN ASCII advanced parameter to write intermediate files in ascii format.