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Decreasing Drag Coefficient (Cd) with Increasing Mesh Quality (3D sphere in a box, turbulent flow)
Posted 1 mag 2024, 06:58 GMT-4 Computational Fluid Dynamics (CFD), Mesh, Results & Visualization Version 6.2 0 Replies
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Hello COMSOL Community,
I'm working on a project where I need to calculate the drag coefficient (Cd) of a 3D sphere positioned inside a box. I have experimented with varying mesh qualities, starting from a coarse mesh (physics-controlled mesh) to assess the balance between accuracy and computational effort.
However, I'm encountering an issue where the calculated drag coefficient (Cd) consistently decreases as the mesh quality improves. For my calculations of the drag force, I am using "Id(?∗spf.nymesh)" where Id is the integration over the sphere’s surface to compute the drag force.
My drag coefficient Cd is calculated by: 2/(AUin^2rho0)Id(pspf.nymesh). A is set to pi*R^2.
As the mesh is refined, the value of Cd gets progressively smaller. Can anyone help me understand why the drag coefficient decreases with better mesh quality?
Any insights or suggestions on how to tackle this issue would be greatly appreciated.
Thank you!
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Hello Kübra Tekbiyik
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