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How to reduce instability caused by inlet perturb?

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Old   June 2, 2006, 11:02
Default How to reduce instability caused by inlet perturb?
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The artificial perturbation imposed at the inlet is the sum of three sinusoidal functions with the same frequency (1.8 randian/s and f=0.3Hz)and different phases. And it is concentrated in the shear layer, the numerical scheme I use is extended MacCormack--- a explicit time integration method. while I take a nondimensinal timestep=0.01, the result oscilates intensily at the inlet, mass density and temperature decrease to a unphysical extent. How to solve this problem, please help!
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Old   June 2, 2006, 11:21
Default Re: How to reduce instability caused by inlet pert
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Without seeing your problem firsthand, I'll offer this... It seems like some sort of entry shock. Could be numeric, or physical.

Perhaps you could offer a few more insights on your model?

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