Fan Diffuser
 

Has anybody simulated an outlet diffuser on an axial fan. I am running some moving reference frame simulations with a mixing plane and without the diffuser I am seeing mass flow rates in line with the expected data sheet values. However I am seeing no increase in flow rate when I add the diffuser. Increase should be around 13%. I have tried some standard solution, increase inlet and outlet plenum size, refine the mesh. Has anybody dealt with this problem specifically before.

Thanks,
John

This is most likely a result of your model/setup. Can you share some pictures of your domain/model to get a feel for what you are actually trying to analyze?