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-   -   FDM. & FVM. (https://www.cfd-online.com/Forums/main/2591-fdm-fvm.html)

H.Setthapong September 12, 2000 09:42

FDM. & FVM.
 
Can anyone tell me,How difference between Finte difference method and Finite volume method.?

Istadi September 13, 2000 00:05

Re: FDM. & FVM.
 
It is any difference between FDM and FVM. In the FDM method, the differential terms are numerically approach directly by Taylor series, i.e. first order or second order. The second order have a good approximation with less error. In the FVM, the differential terms are firstly integrated analitically in the control volume between left face to right face. After that, the differential terms are numerically approximate by Taylor series or schemes , i.e. hybrid, power law, upwind differencing, etc, by applied conservation of mass and energy throughout control volume.

In the FVM, it is more and more rule of law that we must obey to get stabil and real solution.


sameer mohrir September 13, 2000 01:20

Re: FDM. & FVM.
 
You can refer to question posted by myself on 17th Aug 00.regarding same subject

regards

sameer mohrir

H.Setthapong September 13, 2000 10:01

Re: FDM. & FVM.
 
Hello,Istadi Is that means the SIMPLER METHOD with POWER LAW is also FINITE VOLUME METHOD.? Thank for your help.

H.setthapong

Istadi September 13, 2000 22:26

Re: FDM. & FVM.
 
In the FVM, there are SIMPLE method and SIMPLER method. Patankar (1980) said that SIMPLER method is modified of SIMPLE method in order to achieve fast convergence.

Sebastien Perron September 14, 2000 06:47

Re: FDM. & FVM.
 
As far as I know,

1) The simple (Simpler, Simplec etc) method is not a numerical scheme (FVM, FDM FEM). It is an algorithm related to projection methods, these are used to solve incompressible flow.

2) But it is widely used in FVM codes to solve incompressible flow. (That is why when people say they use Simple or Simpler we often beleive it is in the context of FVM)

3) It is also used in some FEM codes to solve incompressible flow.


Istadi September 15, 2000 05:37

Re: FDM. & FVM.
 
I agree with your opinion that SIMPLE or SIMPLER is not a numerical scheme. As far as I know that the numerical scheme are power law scheme (PLS), upwind difference scheme (UDS), hybrid scheme, etc.


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