Forces.C code explaination
 

Hi,

I have two questiosn belonging the following code:

Does anyone know what is meant by Sfb and RhoReffb or Reffb? I think Sfb is the area of the face i. "dev" subtracts the trace from the tensor. RhoReffb should be something like mu*grad(u).

Ok I found out that R() represents the reynolds stress tensor.

Reff() is the effective stress tensor, does anyone know what is meant by effective here?

Any why there is a "b" at the end of Sf "b" and RhoReff "b"()? Boundary maybe?

Pool Gor mathematics, numerics, derivations and openfoam. There you find the definition of DevRhoREff

Thanks, that helped a lot.

Just two more question: Why is there a "b" at the end?

In "devRhoReffb" Rho is stands for a density based equation. I am calculationg an incompressible case and still getting values of it. Does this equation represent a general Approach to calculate fT?

Maybe something changed, I am using OpenFOAM 4.1.

As we are only interested in the force acting on a patch, the b postfix just shows one that it is related to boundary values, which can be already seen in the snipped you provided. You can name the variables as you want.

Ok thanks I thought that.

Btw I have found out that for the incompressible case devRhoReff equals devReff.

Ok so the last part that I am missing is the missing normal vector. There should be a normal vector for calculating the pressure force and another one for the friction force. Are they in Sfb[patchi]?