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#1 |
New Member
Join Date: Nov 2012
Location: Scotland, UK
Posts: 19
Rep Power: 14 ![]() |
Hi
I've been using simpleFoam to analyse our FSAE car and then later develop an aero kit for it. I'm using a k-w SST model and see below for problem outline. I have 7 patches/ .obj's, 4 wheels, chassis+driver+engine, nose and side panels, and suspension. They are refined (6 7) except for the chassis which is (5 6) and each cell outside refinement region is 1m cubed. ![]() The omega is wrong in the image, using 0.622, reduced size of boundaries as well to x=60m, y=10m, z=8m. Refinement box is also slightly reduced. So I have run it at 12.5m/s and it worked ok, you can see the residual below. I've tried many variations and simplifications of geometry, however the oscillations don't disappear. I believe this is cause by vortexes being shed from the wheels. The blue line represents 12.5 m/s, and the red 15 m/s - basically I want Cd, Cl, and Cm values, however I want to ensure they are velocity independent which is why I'm running for velocities above and below 12.5. ![]() The settings are identical for both except @ 20m/s, k = 0.135, w= 0.745. my fvSolution file is based off of the motorBike tutorial, and the only changes are relTol = 0.001, and tolerance is at 1e-09. fvSchemes is untouched and is identical to the motorbike case. as you can see the solution blows up, and it happens 9 times out of 10, with different settings, I've no idea why this is happening or how I can prevent it, any help would be appreciated. I am running this case in parallel and used the scotch method for decomposing. Using 4 cores. Last edited by GPan1; December 2, 2012 at 18:36. |
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#2 | |
New Member
Join Date: Nov 2012
Location: Scotland, UK
Posts: 19
Rep Power: 14 ![]() |
Right so i narrowed it down and it could be the mesh causing this, I get an error with skewed faces, any help in solving, or fixing this mesh would be appreciated.
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Tags |
car, divergence, residuals, simplefoam |
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