Oscillation of residual and monitoring points

CFXer · August 8, 2020, 01:14

Hello.

I'm trying to simulate the full-scale heat exchanger using porous media approach to the core part. So I modeled the whole heat exchanger and tried the simulation.

As I attached a picture, the residual and user monitoring points keep oscillating, do not converge.

In order to ensure the convergence, I have set the timescale factor to 0.1s (especially in the picture 0.01s) but it doesn't converge well.

I have searched how I can ensure the convergence in CFX, but most of the posts are said 'timescale factor', but it doesn't work well.

Does anybody have an idea of convergence? I think I must make this simulation converge.

Thank you in advance.

ghorrocks · August 8, 2020, 04:15

FAQ: https://www.cfd-online.com/Wiki/Ansy...gence_criteria

There is a lot more to do beyond just the time scale factor. See the FAQ for details.

August 8, 2020, 04:15		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	FAQ: https://www.cfd-online.com/Wiki/Ansy...gence_criteria There is a lot more to do beyond just the time scale factor. See the FAQ for details. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

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