Entries for April 2013

danobis, here is a working example of a journal files (.jou), when you see a ";", it means i'm asking fluent to skip that command:

/file/read-case-data /home/maghazlani/Analysis/intake_test_3-1-23000.cas
;/define/operating-conditions/operating-pressure 0
;/define/models/solver/density-based yes
;/define/models/energy yes
;/define/models/viscous/kw yes
;/define/boundary-conditions/modify-zones/zone-type 11 pressure-inlet
;/define/materials/change-create...

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...

Pseudo 2D results is here on the graph


Cx is predicted very well, so let's make a comparation with 2D results



The difference is really big on supercritical angles, the PISO's results on 2D tetra meshes were also bad and quite similar to the 2D hexa's results.

So, it's better to use PISO with symmPlane or slip BC on domain's sides

#OpenFoam #2Dairfoil

It seems there is big difference in case with 1-cell thick domain where we set empty BC compare to case with 5-cells or 3 - cells thick where we set symmPlane

for SST and NACA23012 we have (17 and 15 grad angle of attack)



So when we use PISO, it would be better to use 5 or 3 -cells thick domain.

A certain Mahdi wrote me via e-mail, that my tetra-mesh and hybrid mesh was not good for simulations.

So here i show results which were obtained with C-mesh generated by blockMesh utility OF, and snappyHexMesh.

blockMesh domain



mesh near wall



snappyHexMesh domain



boundary layer discretization


...