Hi My problem involves unidirectional flow along the X axis its an external flow problem with body over which the fluid is flowing being symmetrical about the X axis. To my surprise when i'm constructing a structured mesh i'm not getting any force in Y and Z direction, but a non zero force value when i'm using tetrahedral cells.

Hi,

Is it a significant force? You will not get exactly zero force, but if the flow is truly symmetrical it should be an insignificant force.

Alternatively if the flow is non-symmetric then you could be seeing a non-symmetric wake. Then there will be a significant cross force.

Glenn Horrocks

Ya, as i said the force is significant if i'm using unstructured mesh; but not in a hexahydral mesh case.

Have you done a mesh refinement study?

ya quality is fine. and mesh is getting exported.

Hi,

Brunoc was asking about a mesh refinement study. This checks whether the mesh size you are currently using is adequate to resovle the important features of the flow. This is a different thing to mesh quality.

Regards, Glenn Horrocks