I have modelled up a small centrifugal fan (Scroll + Impeller ~40mm O.D.) and now I would like to obtain its characteristic performance (P-Q) curve.
My blower is discharging into an open environment (atmospheric pressure / room temperature)
I have set up my simulation the following way:
-Internal Analysis + local rotating region
-Fluid medium: air
-Rotating speed of the impeller: 7000 rpm
-Real wall bounbdarr on the scroll walls
-Local Initial mesh on the impeller body
Now I am strugling to understand how to set up the next two BCs. Which is the correct way?
- Define the Inlet Static Pressure and the Environmental Outlet Pressure and solve for Outlet Flow rate?
- Define the Inlet Flow rate and the Environmental Outlet Pressure and solve for Inlet Static Pressure?
Ideally my intuition says that If I want to find the Pressure as a function of Flowrate [P(Q)], I should set the Outlet Flowrate and then let the solver compute the inlet Pressure.
But apparently I cant define both the Environmental Pressure Condition and the Outlet Flowrate on the outlet Lid.
So what do you think guys? Will option 1 or 2 give me the proper PQ characteristics or do I have to follow another approach that I haven't thought of?
I would welcome your thoughts and suggestions.