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Old   August 17, 2011, 14:10
Default Bulk velocity
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Miguel Caro
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Hello,

i am trying to simulate a turbulent flow around a wall-mounted cube using the kappa-epsilon model and, in a future, the RNG- kappa-epsilon model.

The Reynolds number based on the bulk velocity and the channel height (Re=U_b* H/nu, U_b bulk velocity, H cube height and nu cinematic viscosity) is Re=40000.

But , excuse me for this question: How i compute the bulk velocity?

I am using to simulate this problem an in-house code for turbulent flows , for this i need the inflow velocity , Uo ,to start the simulation. The H value is done as the Re above mentioned.

The initial and boundary conditions are taken from Lakehal and Rodi,"Calculation of the flow past a surface-mounted cube with two-layer turbulence models", 1997.


regards
Miguel
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Old   August 18, 2011, 10:02
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Turbulent flows, S. Pope, "wall flows", p.p.264-280.
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Old   August 22, 2011, 06:23
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Rami Ben-Zvi
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u_{i,bulk} = \int_{\partial V} \rho u_i dA / \int_{\partial V} \rho  dA
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Old   March 19, 2013, 08:06
Talking CFD happy ending thread
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Jose Rey
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Does my question answer your question?

I asked (paraphrasing):

Quote:
The stressComponents postprocessing utility (utilities/postProcessing/stressField/stressComponents.C) provides a Ub vector (x,y,z) mapped on surfaces. What is the physical meaning of Ub?
I know this is a pretty old thread, but this might give it a happy ending.
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