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Surface roughness fluid flow
Posted Jun 3, 2022, 3:01 p.m. EDT Fluid & Heat, Computational Fluid Dynamics (CFD) Version 6.0 2 Replies
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Hi, I would like to add different surface roughness for a simple channel flow case. I see the option to do that for any of the turbulence models under the Turbulent Flow interface. But, is there a way we can add it for laminar flow? Is it the practical limitation that surface roughness can induce turbulence, that we don't have this option in COMSOL?
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One way would be to examine the surface roughness terms added into the turbulence model equations (view equations). Then retrieve those terms and save them to a temporary file. Next add those same terms into your laminar-only equation system in a similar manner as the turbulence equations. Take care to make sure all the variables/parameters used in these terms are correctly coupled and implemented. This will require you to understand the physics required for this term. Then test it out.
Alternatively, you could add the effect of the surface roughness through a body-force term which would be more of a global effect and cause an overall pressure change due to the surface roughness (see the implementation equivalent in 1D to understand).
-------------------James D. Freels, Ph.D., P.E.
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Hi James Thank you, this is very helpful. It definitely would be useful if this was a term directly available under laminar flow since the links already exist for turbulence.
I'll give this a shot. Thanks !
Advitya