Poor mesh quality

Hello, developer. I want to simulate a reactor, but partitioning a grid that satisfies the calculation is too difficult for me. I tried again and again for a day, but the simulation still can’t work properly, could you give me some advice?Thanks!
cone2_2023-03-15T181716.506568.zip (160.8 KB)

There is a conflic between your stl file (no slip wall BC) and the right outlet BC. As a quick fix. i sligthly decrease xmax and added vertical walls to remove the conflict. Please see attached.

cone2.mfx (22.5 KB)