CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   The turbulent viscosity on the wall (https://www.cfd-online.com/Forums/main/5680-turbulent-viscosity-wall.html)

maximus January 23, 2003 12:07

The turbulent viscosity on the wall
 
Hi,I use the K-e model along with an one-equation model in the near wall region.How to evaluate the turbulent viscosity (Mut)on the wall?Is it equal zero?From the one equation model,the turbulent viscosity in the near wall region is evaluated as :Mut=Cu*sqrt(k)/Lu,where Cu is the constant for k-e model and Lu is the length scale. Should I get Mut from the above formulation ,or set it to zero?Which is reliable?Thanks a lot. maximus

Fabian January 24, 2003 03:49

Re: The turbulent viscosity on the wall
 
The turbulent shear stress is tau_t=rho*u'*v' (1). In eddy viscosity models you assume tau_t=rho*mu_t*du/dy (2). From equation (1) you see that the turbulent shear stress is zero at walls. So take a guess which term in equation (2) has to be zero in order to follow this condition?

maximus January 24, 2003 04:02

Re: The turbulent viscosity on the wall
 
It must be mu_t to be the zero term.Thanks.


All times are GMT -4. The time now is 07:31.