[shariq12]

Hello,
Iam simulating a symmetrical 3d diffuser for the following boundary conditions:
Inlet: velocity inle: 35m/s
Outlet : Gauge pressure : 0
Engine outlet: Mass flow outlet: 30kg/s
remaining are set to be engine walls as shown in the figure 1

However doing this causes no total pressure drop within the diffuser due to the walls (as shown in the attached image), the total pressure drops on the outter walls but for some reason it does not drop on the inner walls of the diffuser.
If I run the same but change my engine mass flow outlet to pressure outlet and adjust to a negative gauge pressure iam able to see the effect of drop of total pressure on inner walls of the diffuser.
Can someone help me out, I want to maintain a constant mass flow of 30kg/s at diffuser exit with inlet velocity at 30m/s.
Please do correct me if im wrong somewhere.

1.PNG

2.PNG