Unfortunately, it was not possible to do all the tests in the simulation. The program complained about the geometry and crashed when I tried.
But there is another method to test, but then I must have a solid STEP file as well. The solid is used to simulate the air volume inside the nozzle and it must have exactly the same outer geometry as the nozzle but no cavities.
Otherwise, you will be happy with these pictures. The pictures show areas where the air velocity is at its highest, ie. narrow passages. In those places where the flow is throttled, you should try to make the channels larger.