Turbulence modeling
Hi all
I'm simulating flow around sphere at Re=1E05 with DES(Detached Eddy Simulation) turbulence model. the Y plus=0.2 and time step size=0.008. The mean drag coefficient is 0.27 and there is large error with experiment data that say Cd=0.42. whats wrong in my simulation? Best regards. omid |
use the gamma theta model
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Could be dozens of things, not just the turbulence model. Read this FAQ:
http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F |
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Try to solve it with the timestep of order of 1e-4... it may work.. mesh density along the chord and in downsteam also are important. good luck:) |
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Hi Thanks but its very small! i use timestep value equal 0.008 but the Drag be constant, i think with smaller timestep this problem repeat, whats your idea? |
Thanks all
I find something about grid resolution and surface grid spacing in ANSYS CFX- solver theory guide p.81 : DES simulation. is this problem because of grid induced separation? |
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regards |
I am having a similar issue. did you ever get to the bottom of this?
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