How to solve this formula?
 

Hi guys,

I am a newbie on this model. I need you help on this. This is a model called gao-yong turbulence model.

"Partial-average-based equations of in-compressible turbulent flow"
Ge Gao. Yan Yong.

In this model, we have a equation like this:see the attached image.

We know u and p. tau can be expressed by vector l.

The right of this equation is a little different with the normal N-S equation. There is a vector l , and the whole right part, which is different with the N-S equation, is a inner product of two vectors. Im using FVM. So now I dont know how to discretize it. Any ideas will be appreciated. Thanks in advance.

Any ideas? Thanks.

A little progress:

In the equation I posted, I should solve the mag(l). But how? I dont know.