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-   -   C programming question eg simpleFoam (http://www.cfd-online.com/Forums/openfoam-post-processing/61332-c-programming-question-eg-simplefoam.html)

marc_wattenberg January 27, 2009 08:57

Hi together, I am currently
 
Hi together,

I am currently working on understanding the basics of the solver code. I am a litte bit familar with programming, but do not understand e.g.

UEqn().A()
UEqn().H()
mesh.Sf()
etc

For me its clear that some fuction A,H,AU... will act on the momentum equation, but where is the function defined. I already searched in the source guide but can not find A or H. I am sure someone can tell me the right procedure for understanding this

Thanks a lot
Marc

grtabor January 27, 2009 09:05

This is part of the PISO algor
 
This is part of the PISO algorithm. The momentum equation can be written as

a_p U_p = H(U) - grad(p)

for a point p. We need to be able to rearange this to solve it. .A() and .H() give access to the relevant components; roughly the diagonal of the matrix and the off-diagonal non-pressure components, respectively.

.Sf() gives the face normal vectors IIRC

Gavin

marc_wattenberg January 27, 2009 09:12

Thanks Gavin, but this was
 
Thanks Gavin,

but this was clear to me. I want to know where to find the definitions of A()... inside the code

Marc

grtabor January 27, 2009 19:32

Dear Marc, Try rummaging ar
 
Dear Marc,

Try rummaging around in OpenFOAM-1.5/src/finiteVolume/fvMatrices

Gavin


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