Simulate Secondary Flow Blockage
 

How would I simulate secondary flow blockage in CFX 12.1? Basically it's a heating coil with 2mm-gap fins that's in front of the Opening. Experimental results show an entrainment ratio one whole value less than my CFD results without secondary flow blockage, ie, 5.2 vs 4.2

I tried the "Loss Coefficient" setting under Boundary Details in Setup, but that didn't do much. Even at 90%. Any suggestions?