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Yahoo June 5, 2013 15:53

pRefCell on Parallel Simuations
 
Hi
I have developed a solver which works fine on single processor, but diverges when I am running it on multiple processors. For the later, by changing the cell at which pressure is set (pRefCell), my results change. i.e. pRefCell is affecting the results on parallel simulations! Any hints?

cfdonline2mohsen June 10, 2013 05:58

Dear Yahoo
As you know pressure is a relative quantity in numerical calculations because it it 1st order (e.g. dpdx in Navier-Stokes Equation). in order to assign absolute values for pressure you Must fix the pressure at one point of your simulation that you know the pressure (for example you can fix the pressure at one point in outlet if it flows to atmosphere).
so it is evident that if you use different values for pRefCell, you will obtain different Absolute Pressure but the relative pressure between 2 points will be the same.

Best Regards
Kia


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