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-   -   Convective Schemes how are they implemented (http://www.cfd-online.com/Forums/openfoam-solving/59089-convective-schemes-how-they-implemented.html)

nicasch February 28, 2008 11:44

Dear OF users and developers,
 
Dear OF users and developers,

I would be very grateful if anyone could please provide some insight into the following divSchemes:

- Gauss limitedLinearV
- Gauss interfaceCompression.

I suppose that they do some kind of blending based on the blending factor (limiter) calculated according to the scheme used. Is this blending between linear UD and CD or something else?

I found a post containing the following:

Φf =ΦC +(xf – xC) *ψ(rf) * (dΦ/ dx)f
Or
Φf =ΦC +(xf – xC) / (xD– xC) *ψ(rf) * (ΦD-ΦC)

f ,the face
C,central node
D downwind node
ψ(rf) the flux limiter

rf is based on the following formula
rf=(ΦC-ΦU)/( ΦD-ΦC) = 2*grad(ΦC)*(xD-xC) /( ΦD-ΦC) -1

I get bit confused while trying to read the code, is there any written text about these two schemes, or can someone please explain how they work?

In limitedLinearV, I suppose that it is a kind of limited CD, but how is the scheme limited? Where is the limiter for this scheme used? Is the limiter function phi(r) used in calculation of the face value using adjacent cell-center values (like normal CD), or is it a blending between linear upwind and CD?

For the interfaceCompression scheme I suppose that it is some blending based on the blending factor calculated according to the either quartic or quadratic formula. Where is the limiter for this scheme used?

Many thanks in advance, best regards.

santiagomarquezd November 4, 2010 10:47

Nicasch, have you finally found an explanation for interfaceCompression scheme? I'm struggling with the same question.

Regards


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