Reno Genest
Ansys Employee

Hello Arnaud,

Make sure the surface mesh is watertight; the surface mesh should fully enclose the volume mesh with no holes or gaps. Also, the mesh has to be conformal.

Have you tried to use all triangles for the surface mesh? 

Also, the boundary layer is specified for the volume mesh using *MESH_BL. Make sure you don't have special mesh features that could complicate the mesh. Start simple and have a successful volume mesh. Then, add complexities one-by-one.

If you have access to the Ansys Learning Hub (ALH), you can acces the ICFD training course:

https://jam8.sapjam.com/groups/QyHAlhciRCZ0Xt6xKZ2MHi/overview_page/jPMouxqQ2AOP6jVZLBMZCl

Note that Ansys employees are not allowed to upload or download files on the Ansys Forum. So, I cannot look at your model, but maybe another user could.

If you are a commercial customer, you can create a support case on the Ansys Customer Support Space (ACSS) and we will have a look at your model:

customer.ansys.com

 

Let me know how it goes.

 

Reno.