I imported your project and tried to ramp the inlet velocity, didn’t get the expected results though. The mesh requires changes near the smaller geometry features, since the compressible flow solver is sensitive.
A suggestion is to increase the refinements next to the geometry. You can also introduce another ‘Cartesian Box’ just around the geometry in order to have a fine mesh and decrease the refinement one/two level/s down in the existing box. By this way you can maintain lesser mesh elements, thereby saving computational time.
Hope this works! Good luck and curious to see the results