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Problem with vortex shedding frequency

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Old   September 26, 2014, 08:31
Default Problem with vortex shedding frequency
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Saravana Kumar Lakshmanan
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Hi friends,
I am currently trying to simulate flow past a circular cylinder for my thesis in OpenFOAM. I am having problem in getting the correct strouhal number. Drag coefficient is comparatively good. The following are the BCs and details about mesh


Dia=0.034 m; velocity=20 m/s; Re=45,000 ; Solver- PISOFOAM; RANS Model-kOmegaSST


P-freestreamPressure at inlet & outlet, zeroGradient on cylinder (wall), Symmetry on Top & Bottom


U-freeStreamVelocity at inlet & outlet, fixedValue (0) on wall, Symmetry on Top & Bottom


k-fixedValue at inlet (based on k=3/2(UI)^2),zerogradient at outlet, FixedValue (0) on wall and kqrwallfunction, Symmetry on Top & Bottom


omega-fixedvalue at inlet & outlet (based on omega=k^3/2/kcmul) basically took from one journal paper.For wall omega wall function and value =60nu/betaXdely^2. Symmetry for Top & Bottom


nut-fixedvalue(0) at inlet, zerogradient at outlet,nutuspaladingwallfunction on wall, symmetry on Top and bottom.


Mesh details:
Y+=1, Four meshes are tested 50K,65K,80K,and 95K with max aspect ratio less than 22. The domain size is sufficiently long was used.
fvSchmes:


Time- Euler, gradschmes-Gauss linear, Divergence-Gauss limitedlinear,Laplacian-Gauss linear corrected
Interpolation-linear, Sngrad-corrected


Fvsolution:
PCG with DIC as preconditioner for pressure with tolerance of 1e-06, reltol=0
For other terms PBiCG with DILU ,tolerance 1e-08


Ncorrectors=2,northogonalcorrectors=3


Please help me to solve this friends, Hope I described all important details
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