CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Main CFD Forum (
-   -   Bulk velocity (

mcaro August 17, 2011 14:10

Bulk velocity

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.


mcaro August 18, 2011 10:02

Turbulent flows, S. Pope, "wall flows", p.p.264-280.

Rami August 22, 2011 06:23

u_{i,bulk} = \int_{\partial V} \rho u_i dA / \int_{\partial V} \rho  dA

JR22 March 19, 2013 08:06

CFD happy ending thread
Does my question answer your question?

I asked (paraphrasing):


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.

All times are GMT -4. The time now is 06:09.