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Tolerances and time stepping in transient simulations
Posted 26 nov 2014, 09:15 GMT-5 Heat Transfer & Phase Change, Studies & Solvers 0 Replies
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I try to simulate the transient heating (about 2s) of air on top of a small microheater using the conjugate heat transfer model. The temperature of the heater is fixed at 250 °C while the initial temperature of the ambient air is 25 °C.
The problem is that for short times the temperature increase at a point close to the heater depends on the used time stepping of the solver, independent of the used absolute tolerance. Here, I compared the values at the "steps taken by solver".
To get precise results, I always try to use very small time steps at the beginning of the heat pulse and select the intermediate stepping. But this means that I have to repeat the simulation and adapt the time steps every time to increase the accuracy without increasing the needed simulation time too much.
Is there any hint or rule of thumb about how to choose the tolerances or time stepping?
Thanks in advance
Bastian
Hello Bastian Schmitt
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