AnsweredAssumed Answered

Flow results do not correspond to input fan curve

Question asked by Amit Katz on Dec 10, 2015
Latest reply on Apr 12, 2019 by Bill McEachern

Good morning fellow Flow Sim users!


I am working with fan curves for the first time, and I'm a little confused about how the software handles them. I simulated an air manifold with an external outlet fan. When I look at the surface parameters of the face that I assigned the fan to, I get these data:


Local ParameterMinimumMaximumAverageBulk AverageSurface Area [in^2]
Pressure [in H(2)O]280.11289.56285.97285.972.1425
Density (Fluid) [kg/m^3]0.830.860.850.852.1425
Integral ParameterValueX-componentY-componentZ-componentSurface Area [in^2]
Mass Flow Rate [lb/s]-0.12632.1425
Volume Flow Rate [ft^3/min]-142.82052.1425


However, my fan curve looks like this:

fan curve.PNG


A flow rate of 143 CFM is right around the 172"WG mark on my curve, but according to the software the pressure difference at my outlet fan is 407-286 = 121"WG. So what gives? I should be getting either a lot of more or a much higher pressure difference.