[Friendly]

Hi,

I have two questiosn belonging the following code:

vectorField fN
(
rho(p)*Sfb[patchi]*(p.boundaryField()[patchi] - pRef)
);

  vectorField fT(Sfb[patchi] & devRhoReffb[patchi]);

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).

[Friendly]

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?

[Tobi]

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

[Friendly]

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.

[Tobi]

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.

[Friendly]

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]?