Coarse mesh problem in outer part of main blade boundary layer control block
 

Hi Everyone,

I have been meshing a transonic impeller blade in TG. Since the trailing edge is cutoff the only topology option TG offers is "Single Splitter". In the meshing job, transonic flow features (leading edge shock, passage shock) can only be captured by a fine mesh around leading edge. I am able to refine the mesh blocks by increasing the edge split factors, however main blade boundary layer control always results in very coarse elements adjacent to other refined blocks as seen in the figure. The details of the mesh data is also in the attachments. I have a good BL resolution with a first element height of 1 micron and I tried to keep the expansion rate as low as possible to avoid coarse cells outer part of the main blade BL control block. Is there any way to handle this problem ?

I look forward your recommendations.

Thank you

Bora

I know this issue as well. It's really stupid. Many versions ago, it was possible to move the nodes of the blocks manually. Now, it's not possible anymore.

One idea, although it won't help much, is to play with the five edge vertex slider. Maybe a reduction helps a bit to decrease the expansion ratio

Thank you for your reply Zacko. I tried that as well, but did not work unfortunately.

I have contacted ANSYS support and proposed them to create a different topology which its outer edge of main boundary layer control block is more parallel to blade suction surface.

In case they supply me I will share the new topology and mesh under this thread.

Thank you, that sounds great. Hopefully they will adjust the topology in the future