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Boundary conditions for time varying crosswind

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Old   September 7, 2013, 02:31
Default Boundary conditions for time varying crosswind
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Marijo
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Hello,

I am trying to simulate a time-varying crosswind.
I am having a problem with boundary condition set-up.

If I want to simulate only the head wind, the set up is: inlet velocity, pressure outlet and lateral symmetry.
If I want a steady crosswind then the boundary condition set-up is: head and side inlet velocity, and back and side pressure outlet.

The problem comes when I need to simulate transient crosswind. My understanding is that I need to initialize with head wind and therefore the appropriate boundary conditions and than continue with introduction of crosswind. But I need to change the boundary condition appropriate for crosswind. If I switch the bcs the convergence is bad, the simulation needs time to adjust.

Can I have one boundary condition set-up for both cases: headwind and crosswind, so I don't need to change bcs?

Thank you!

Marijo
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Old   April 10, 2015, 04:44
Default Did you solve it?
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Anikethan
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Dear Krembil,

Did you find the solution for this problem ? I have similar setup. I am doing an unsteady crosswind simulation over the bus to check how CoP veries. Can you please tell me how did you do it. I have 2 weeks to complete the project and stuck with it. my guide is unaware how to do it.
Quote:
Originally Posted by krembil View Post
Hello,

I am trying to simulate a time-varying crosswind.
I am having a problem with boundary condition set-up.

If I want to simulate only the head wind, the set up is: inlet velocity, pressure outlet and lateral symmetry.
If I want a steady crosswind then the boundary condition set-up is: head and side inlet velocity, and back and side pressure outlet.

The problem comes when I need to simulate transient crosswind. My understanding is that I need to initialize with head wind and therefore the appropriate boundary conditions and than continue with introduction of crosswind. But I need to change the boundary condition appropriate for crosswind. If I switch the bcs the convergence is bad, the simulation needs time to adjust.

Can I have one boundary condition set-up for both cases: headwind and crosswind, so I don't need to change bcs?

Thank you!

Marijo
Anikethan is offline   Reply With Quote

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