Learning Forum

[Eoin O'Hara]

I am trying to create a couette flow with a sphere in a channel (ansys fluent). The couette flow can fully develop in an empty channel but adding a sphere prevents the flow from fully developing for some reason. Refining the mesh doesn't change the results and only seems to make it more difficult for residuals to converge.

The channel is 5mmx100mm and the sphere is 1mm diameter. Widening the channel also seems to make no difference.

This is the profile of velocity in the chanel. It is supposed to be a strait line but I can't figure out why it isn't.

This is a velocity vector plot around the sphere.

Any help figuring this out would be greatly apreciated.

[Rob]

The images didn't upload correctly. Please can you repost. How well resolved is the mesh, and how well converged is the solution?

[Eoin O'Hara]

The solution converges to 0.000001 and the cell size is 0.5mm Hopefully these images should come up.

[Rob]

Hmm, couple of problems. The mesh isn't sufficiently resolved and has too rapid a growth rate, have a look at the various studies in the literature.