3 Replies Latest reply on Dec 11, 2015 6:27 PM by Kim KyuHyung

    Flow results do not correspond to input fan curve

    Amit Katz

      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.