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November 9, 2024, 17:03 |
Please help me get better residuals
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#1 |
New Member
Adam
Join Date: Nov 2024
Posts: 1
Rep Power: 0 |
I am currently attempting to run some CFD simulations for the rear wing of a formula student car, however i am having some issues getting the residuals to converge properly, specifically the Tdr residual.
I am using steady state solver and segregated flow, with K-epsilon turbulence. I am quite certain that my setup should be steady state with no time dependent variables. Also i have 5 prism layers, with a total prism layer thickness of 0.008m. I have a very fine mesh so i don't believe my issue lies here. Also i am using a velocity inlet with 20 m/s and a pressure outlet at 0 Pa located 25 meters back from the inlet. I have attached a copy of the residuals i have received. This is the second running of the sim so i know that the Tdr residual doesn't converge more with further iterations. I would greatly appreciate any help/ideas on how i can improve the residuals. |
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November 15, 2024, 11:53 |
Adjust normalizing factors
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#2 |
Member
Arvind Jay
Join Date: Sep 2012
Posts: 97
Rep Power: 15 |
I don’t see any major issues, as these are scaled residuals. For Tdr convergence, here are a few suggestions:
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November 20, 2024, 15:00 |
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#3 |
New Member
Join Date: Mar 2011
Posts: 22
Rep Power: 16 |
I agree, the results don't look too bad. I would not rely on those too much but rather on the quantities that you are interested in.
Add some monitor points and observe mass flow rates, pressure drop, max + avg quantities, etc. Use those to judge your convergence. Residuals are nice for quick info, but I would always analyze the relevant quantities. |
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Tags |
aerodynamics, cfd, formula student, residuals, turbulent dissipation |
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