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rtech October 4, 2012 05:48

Drag Coefficient depending on the Reynolds' number.

I'm trying to found a numerical model that represents approximately the following experimental curve :
As you can see, it represents the drag coefficient depending on the Reynolds' number in the case of a sphere. Thereby, I use very high Reynolds' number, from 10⁴ to 10⁷. Unfortunately, I can get “right” drag coefficients. I'm using the simpleFoam solver supposing that my fluid is incompressible of course. I've tried to use the “SpalartAllmaras” RASmodel and the “k0megaSST” one. For example, for the k0mega, I've got those coefficients :

Re=10⁴ → Cd=0.401791
Re=10⁵ → Cd=0.224801
Re=3.10⁵ → Cd=0.168429
Re=5.10⁵ → Cd=0.154445
Re=2.10⁶ → Cd=0.090002
Re=10⁷ → Cd=0.0672258

I just want to know if anyone has an idea of what should I do to get my drag coefficients not far from the experimental ones. Maybe someone has been already confronted to that case...

Thank you.

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