Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
The relation between mesh size and time step in time-dependent study on heat transfer problem
Posted 13.05.2016, 12:03 GMT-4 Heat Transfer & Phase Change, Mesh, Studies & Solvers Version 5.1, Version 5.2 1 Reply
Please login with a confirmed email address before reporting spam
I am simulating heat transfer problem and when it comes to set up the mesh, is there a limit on the max mesh size according to the time step I set up? Say I compute the heat transfer and want to see the temperature distribution in the material each 1ms, is there a requirement for the mesh size due to this condition (or the velocity that heat travels)?
Thanks.
Hello Li-Fan Yang
Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.
If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.
Please login with a confirmed email address before reporting spam
The realtion between mesh size and time step in transient heat transfer study is defined by the thermal diffusivity. This is the heat propagation "speed" through the material. If the conductivity of the material is quite small, the heat will propagate less into the body and if this depth is of the order of the element size, you will get oscillations in the temperature profile, because you can not capture the solution. The critical time step is a direct result of the non-dimensionalization of the heat transfer by the conduction equation: L=sqrt(k*dt/(rho*Cp)).
See:
pruffle.mit.edu/3.016/Appendices/NonDimensional.pdf
Best regards,
Antoni