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Old   March 10, 2013, 16:56
Default Flat plate and Boundary conditions
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I'm trying to compute the flow over a flat plate to study the boundary layer growth.
I'm using the density based solver because my flow is hypersonic (M=8.28).

I'm struggling with the boundary condition before the flat plate. I set a symmetry boundary before the plate in order to avoid interactions between the plate and the inlet.

The problem is that my flow is disturbed near this symmetry plane, where it should not because the flow is supersonic, no information should go upstream. The flow should be completely uniform until it reaches the plate.

At first, the velocity was not constant when I used a symmetry condition for the high boundary.
And then I switched the high boundary to pressure outlet and the velocity issue was fixed, but it appears that turbulent parameters are not uniform before the plate, I would expect them to be.

Do you have any idea what could be causing this problem?

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Old   March 10, 2013, 19:39
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I was thinking about my problem and I figured out that the values of Turbulent kinetic energy and specific dissipation rate near the symmetry plane before the flat plate are the same as the one I applied during initialization.

Would my problem come from the fact that initialization values are wrong? combined with the fact that near symmetry planes, normal gradient are forced to zero?


Edit: I realize that the same was happening with velocity before I change the initial value of velocity
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