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Drag coefficient shows non-realistic values

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Old   December 12, 2022, 03:18
Exclamation Drag coefficient shows non-realistic values
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Hendrik
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Good Morning CFD Engineers!

We did a simulation of a C-shaped geometry (1.5m height x 4 m length) which faces an airstream with the open side of approx. 15 m/s.

In various CFD-Simulations we always got a drag coefficient of approx. 0.8 while Wikipedia-tables shows 2.3 for open half pipe. Client points out, that the 2.3 is realistic from experimental experience.

We did not see changes with different turbulence models or LES Simulation. There was only one simulation where we increase k significantly in the k-epsilon model. In this simulation we got a value of 1.2.

Does anyone have an Iidea what we have to change to reach higher values?

Cheers!
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Old   January 13, 2023, 23:20
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Will Kernkamp
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I would suspect your domain is not big enough or it has the wrong boundary conditions.
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