functionfres_R134a

Calculation of helmholtz derivatives

Extends from Modelica.Icons.Function (Icon for functions).

Information

This function computes the residual helmholtz derivatives of the fundamental equation of Tillner-Roth and Baehr for R134a (1994) w.r.t. to reduced temperature (tau=T_crit/T) and reduced density (delta=rho/rho_crit). The function can be used for special properties depending just on the residual derivative parts.

Inputs

TypeNameDefaultDescription
RealdeltaReduced density (delta=d/dcrit)
RealtauReduced temperature (tau=Tcrit/T)

Outputs

TypeNameDefaultDescription
Modelica.Media.Common.HelmholtzDerivsfHelmholtz derivatives