.BuildSysPro.IBPSA.Fluid.Movers.BaseClasses.Characteristics.power

Information

This function computes the fan power consumption for given volume flow rate, speed and performance data. The power consumption is

P = r_N³   s(V̇/r_N, d),

where P is the power consumption, r_N is the normalized fan speed, V̇ is the volume flow rate and d are performance data for fan or pump power consumption at r_N=1.

Implementation

The function s(·, ·) is a cubic hermite spline. If the data d define a monotone decreasing sequence, then s(·, d) is a monotone decreasing function.

Interface

function power
  extends Modelica.Icons.Function;
  input IBPSA.Fluid.Movers.BaseClasses.Characteristics.powerParameters per "Pressure performance data";
  input Modelica.Units.SI.VolumeFlowRate V_flow "Volumetric flow rate";
  input Real r_N(unit = "1") "Relative revolution, r_N=N/N_nominal";
  input Real d[:] "Derivatives at support points for spline interpolation";
  input Real delta "Small value for switching implementation around zero rpm";
  output Modelica.Units.SI.Power P "Power consumption";
end power;

Revisions

• February 26, 2014, by Filip Jorissen:
  Changed polynomial to be evaluated at V_flow/r_N instead of V_flow to properly account for the scaling law. See #202 for a discussion and validation.
• September 28, 2011, by Michael Wetter:
  First implementation.