CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Expert-param:: Cht diffusion scheme (

PCFD July 12, 2010 09:16

Expert-param:: Cht diffusion scheme

can anybody tell me what the expert parameter cht diffusion scheme does mean? In which cases does it make sense to set it to its none default-values (=1-4 and 6)?

cht diffusion scheme: Specifies the diffusion scheme for CHT solids: 1=central (interior) , central (boundary); 2=posdef coefficients (interior), central (boundary); 3=posdef values (interior) , posdef values (boundary); 4=blended scheme (interior) , central (boundary); 5=posdef coefficients (interior), posdef values (boundary); 6=blended scheme (interior) , posdef values (boundary)

stumpy July 12, 2010 10:14

I can't think of any situation where you'd want to change this. What's the motivation for looking at this?

PCFD July 12, 2010 10:23

It would be nice if you let me participate your knowledge about this expert paramerer.

stumpy July 12, 2010 13:20

The parameter controls the numerical scheme used to solve the heat diffusion equation in a solid. There's different treatment for boundary nodes and interior nodes. posdef = Positive Definite; you can google this to get more details for the definition of Positive Definite. I assume central means central differencing, but don't know for sure. blended scheme would be a blending, presumably between the central and posdef schemes. "values" refers to the right-hand side of the matrix solution; i.e. if you have [A][x]=[b], then [b] are your "values". "coefficients" refers to [A].

PCFD July 12, 2010 13:49


thanks for the information.

All times are GMT -4. The time now is 05:37.