Heat Transfer Simulation

Jagan Adithya Elango
Jagan Adithya Elango Altair Community Member
edited February 26 in Community Q&A

Hello experts,

In a steady-state forced convection heat transfer simulation, is there a distinction between concurrently solving the flow and temperature equations versus solving the temperature equation subsequent to resolving the flow equations?

 

Best Answer

  • acupro
    acupro
    Altair Employee
    edited December 2023 Answer ✓

    If nothing (material properties, etc) in the solution depends on temperature - there should be negligible difference between solving both in the same run versus solving flow first, then using restart to solve the thermal on that solved/frozen flowfield.  With larger models that take a long time to run, two separate runs like this may reduce overall run time.

Answers

  • acupro
    acupro
    Altair Employee
    edited December 2023 Answer ✓

    If nothing (material properties, etc) in the solution depends on temperature - there should be negligible difference between solving both in the same run versus solving flow first, then using restart to solve the thermal on that solved/frozen flowfield.  With larger models that take a long time to run, two separate runs like this may reduce overall run time.

  • Jagan Adithya Elango
    Jagan Adithya Elango Altair Community Member
    edited February 17

    If nothing (material properties, etc) in the solution depends on temperature - there should be negligible difference between solving both in the same run versus solving flow first, then using restart to solve the thermal on that solved/frozen flowfield.  With larger models that take a long time to run, two separate runs like this may reduce overall run time.

    In certain scenarios, particularly in cases involving completely enclosed rotating flows, the energy equation may fail to converge when solved simultaneously with the flow equation. However, in such instances, convergence is often achieved when the energy equations are solved separately after the flow field has been solved or 'frozen'.

    Could you please explain the reason behind this?

  • acupro
    acupro
    Altair Employee
    edited February 26

    In certain scenarios, particularly in cases involving completely enclosed rotating flows, the energy equation may fail to converge when solved simultaneously with the flow equation. However, in such instances, convergence is often achieved when the energy equations are solved separately after the flow field has been solved or 'frozen'.

    Could you please explain the reason behind this?

    Do you have an example set of input/Log files that shows this?  It likely depends on the level of change the flowfield is still experiencing - if the flow is still changing enough that causes changes in the thermal field, we would see that behavior.