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Old   March 13, 2006, 12:36
Default residual oscillation
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philippe
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Hello, I am studying enclosed convection in small cavity and I want to evaluate the influence of gas pressure on thermal plume developped by a heated wire at the bottom of the cavity. Under 5 bar results fit well with experience, but for higher pressure, residual values of continuity start to oscillate. Perhaps somebody could help me ? Thank you. Philippe
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Old   March 13, 2006, 14:22
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mAx
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switch on unsteady solver
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Old   March 14, 2006, 04:04
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philippe
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Ok, but do I use small time step (and it will take a long time) or a large step ? Thank you. Philippe
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Old   March 14, 2006, 04:32
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mAx
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if you ust to large time step, it won't converge. you must compute by hand the time step you need. for instance t=(minimum cell size of your domain)/(maximum velocity you are guessing) I would use adaptive time stepping
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Old   March 14, 2006, 04:38
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philippe
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I am just trying adaptative time step, thank you very much for your answer. Philippe
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Old   March 14, 2006, 04:40
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mAx
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de rien
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