[Cecilia Zhang]

Hi everyone!
I'm now working on a ventilating problem. Since the ventilated space is large while the contaminant source and the ventilating opening are small, I chose to divide the zone into two part. For one part, which contains the air supply jet vicinity and the source vicinity, I use blocks to build structured meshes. For the other part, which contains the walls and the rest of the space, I use unstructured meshes.
First, the problem lies in that after the merging of the two parts, the mesh quality at the interfaces is very low due to the production of pyramids and the number of the meshes is very big.
Then I change to "Fluent meshing", which is a bottom-up method when building the unstructured meshes when selecting the volume mesh method. Then I can build quad mesh on the interface. Then after merging, the quality at the interface is improved.
But I'm wondering if I can build the volume mesh directly from the surface of the structured part (of course after converting it into unstructed meshes), so I can avoid the problem of merging. However, I've tried but failed. I want to know if it's impossible or it is only due to my wrong practice.
Thank you in advance.