recordFourPortFlowResistanceParameters

Parameters for flow resistance for models with four ports

Information

This class contains parameters that are used to compute the pressure drop in components that have two fluid streams. Note that the nominal mass flow rate is not declared here because the model PartialFourPortInterface already declares it.

Parameters

TypeNameDefaultDescription
Flow resistance › Medium 1
BooleancomputeFlowResistance1true=true, compute flow resistance. Set to false to assume no friction
Booleanfrom_dp1false= true, use m_flow = f(dp) else dp = f(m_flow)
Realn12Flow exponent for side 1, n=1 for laminar, n=2 for turbulent
BooleanlinearizeFlowResistance1false= true, use linear relation between m_flow and dp for any flow rate
RealdeltaM10.1Fraction of nominal flow rate where flow transitions to laminar
Nominal condition
Modelica.Units.SI.PressureDifferencedp1_nominalPressure difference
Modelica.Units.SI.PressureDifferencedp2_nominalPressure difference
Flow resistance › Medium 2
BooleancomputeFlowResistance2true=true, compute flow resistance. Set to false to assume no friction
Booleanfrom_dp2false= true, use m_flow = f(dp) else dp = f(m_flow)
Realn22Flow exponent for side 2, n=1 for laminar, n=2 for turbulent
BooleanlinearizeFlowResistance2false= true, use linear relation between m_flow and dp for any flow rate
RealdeltaM20.1Fraction of nominal flow rate where flow transitions to laminar

Revisions

  • June 17, 2026, by Michael Wetter:
    Updated implementation to allow a flow coefficient n that is different from 2. This allows use of the model for not fully turbulent flow.
    This is for Buildings, #4620.
  • January 22, 2016, by Michael Wetter:
    Corrected type declaration of pressure difference. This is for #404.
  • April 13, 2009, by Michael Wetter:
    First implementation.