Notes for running case in OpenFOAM
Decomposition methods in parallel
Posted April 23, 2013 at 02:05 by Tushar@cfd
Updated March 27, 2015 at 06:51 by Tushar@cfd (Minor corrections)
Updated March 27, 2015 at 06:51 by Tushar@cfd (Minor corrections)
OpenFOAM has four methods of decomposition:
(1) simple
(2) hierarchical
(3) scotch
(4) manual
"Scotch decomposition requires no geometric input from the user and attempts to minimise the number of processor boundaries."(for more information refer OpenFOAM website)
We tried to compare "simple" and "scotch" methods. These methods were verified for a test case using similar processor inputs:
Both these methods were given same parameters: "number of subdomain = 2; processor weights (1 1)" :
We took Poiseuille flow: OpenFOAM's ultility files are used for geometry and mesh generation.
Intel Core 2 Duo E8400 / 3.0 GHz processor was considered for numerical works.
Results:
SimpleCoeff method took 7.17 hrs(computation time).
On the contrary, Scotch method took 4:48 hrs(computation time).
By performing similar tests, it was concluded that Scotch method is computationally faster than other available methods.
Note:
Processor weights do have a impact on decomposition method, always try to minimise the weights of processors for improving computation time.
(1) simple
(2) hierarchical
(3) scotch
(4) manual
"Scotch decomposition requires no geometric input from the user and attempts to minimise the number of processor boundaries."(for more information refer OpenFOAM website)
We tried to compare "simple" and "scotch" methods. These methods were verified for a test case using similar processor inputs:
Both these methods were given same parameters: "number of subdomain = 2; processor weights (1 1)" :
We took Poiseuille flow: OpenFOAM's ultility files are used for geometry and mesh generation.
Intel Core 2 Duo E8400 / 3.0 GHz processor was considered for numerical works.
Results:
SimpleCoeff method took 7.17 hrs(computation time).
On the contrary, Scotch method took 4:48 hrs(computation time).
By performing similar tests, it was concluded that Scotch method is computationally faster than other available methods.
Note:
Processor weights do have a impact on decomposition method, always try to minimise the weights of processors for improving computation time.
Total Comments 1
Comments
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Good work. Thanks.Posted April 30, 2013 at 06:43 by skeptik
