[EmedemaT]

Hi everyone. I have some questions about the meshing in REEF3D. Now I´m trying to replicate the tutorial "9.5 Flow around circular a pier".

I know that some people have asked similar things, but I have some question about the meshing around the cylinder.

First of all, I want to ask if the mesh generated with a colid cylinder in the midle is ok (picture "mesh_cylinder").

Second, if the mesh is ok, I want to ask if exist any form to generate a boundary layer with the cells of the mesh around the solid? (I´m talking about that the cells of the mesh around the cylinder adapt the form of it), or if with the mesh generated by DiveMESH (as shown in the picture "mesh_cylinder") works well.

In the tutorial don´t look like the mesh is adapted to the solid (look picture "mesh_cylider_tutrial"), just cut the cartesian mesh. So I´m worried about that afect the results.

Thanks

[kamath]

Hi Pablo,
There are broadly speaking two ways to represent a structure in a fluid field.
One would be as you mentioned, a body fitted mesh and the other is through immersing the body in the field when the mesh is not body fitted.
In the REEF3D framework, the body is immersed in the flow field using an immersed boundary method. The surface of the body is represented using a level set function and the solid-fluid boundary is handled by ghost cells along with the immersed boundary method (GCIBM).
The advantage with a mesh that is not body fitted, is that one sets up a more or less regular mesh and therefore is able to implement high order discretisation schemes providing a better approximation of the fluid flow.

If you are looking at resolving the boundary later flow and using LES etc. you could refine the mesh in the region around the cylinder using the mesh coarsening procedure available in DiveMESH.

Hope that helped somewhat

[EmedemaT]

Thank you very much for the reply!
I'm going to continue with the tutorial