This information is part of the Modelica Standard Library maintained by the Modelica Association.

This is a partial function that defines the interface of valve characteristics. The function returns "rc = valveCharacteristic" as function of the opening "pos" (in the range 0..1):

    dp = (zeta_TOT/2) * rho * velocity^2
m_flow =    sqrt(2/zeta_TOT) * Av * sqrt(rho * dp)
m_flow = valveCharacteristic * Av * sqrt(rho * dp)
m_flow =                  rc * Av * sqrt(rho * dp)

pos	Type: Real Description: Opening position (0: closed, 1: fully open)

rc	Type: Real Description: Relative flow coefficient (per unit)