topic convergence issue with thermal and flow analysis in CFD Forum

convergence issue with thermal and flow analysis

SKDavare — Mon, 04 Apr 2022 09:06:05 GMT

Hello Everyone,

need to simulate server room cooling application shown below.
I am running flow and thermal analysis in steady and then in transient mode . In steady state I observed my temperature values are diverging. I used equation of state or density as function of temperature for steady state analysis and in transient I will be using density as function of temperature.

Internal fans are used to blow air from left sides FAN1 units along with cooling load, steel material assigned with total heat generation. I tried initializing whole air domain with known temperature values in one scenario and without initial conditions in another scenario but both cases results are not varying much. Please help.

Re: convergence issue with thermal and flow analysis

karol.suchon — Tue, 05 Apr 2022 10:36:23 GMT

Hello, from the convergence plot of temperature it looks like your temperature is dropped almost linear by the entire simulation, there is a chance that you have a heat exchanger which produces more cooling power than CRAH units, in that case, the simulation will never end. Please attach the files and I will try to help you.

Best regards,

Karol

Re: convergence issue with thermal and flow analysis

SKDavare — Sun, 10 Apr 2022 15:23:02 GMT

Thank you..

I could able to achieve convergence with changing some boundary conditions. Though in transient mode I am getting failure for my scenario. Will share you case details.

Re: convergence issue with thermal and flow analysis

karol.suchon — Mon, 11 Apr 2022 12:18:27 GMT

No problem, if you attach the scenario file I will look into the simulation and let you know what could cause the issue.

Best regards,

Karol