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Old   February 26, 2006, 12:43
Default Dynamic mesh-compressible problem
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yilmms
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Hi Max, I'm working about compressible(density=idealgas) incylinder3d problem. 3000rpm,staring angle=180 finish angle=720 anglestep=0.5. when preview mesh no problem. but when ı give pressure inlet-pressure outlet and starting iteration continuity gets bad results and crash 250 degre. I change anglestep,iteration per time step,mesh size but every time it crash neary 250-255.I try all k-e k-o reynolds all models but it only change 240 to 245. whats the problem? please give me some advise...
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Old   February 27, 2006, 03:03
Default Re: Dynamic mesh-compressible problem
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mAx
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you seem to have a convergence problem. If it always crash at Time step 250-255, you must inverstigate your mesh for finding high skewed cells. If you get one "bad" cell, it will make your model diverging (I also have similar problem now) Try to modify your MDM set up. You can also try to reduce your time step. Hope it helps
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Old   February 28, 2006, 03:30
Default Re: Dynamic mesh-compressible problem
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yilmms
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max cylinder-teta meshes are more bad when ı use alot mesh than now. do u think that changing relation factor give got result now ı try these...
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Old   February 28, 2006, 08:25
Default Re: Dynamic mesh-compressible problem
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mAx
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are you working with layering, or remeshing (smoothing)?
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Old   March 9, 2006, 03:12
Default Re: Dynamic mesh-compressible problem
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yilmms
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ı'm working 3d remeshing problem. continuity never converge in different time steps. in the same time step it converge but when starting other time step it is bad than first time step. do u have any 3d remesh unsteady case for piston. or have any idea about that...
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