calculation of Prandtl number
function PrandtlNumber extends Modelica.Icons.Function; import MIN = Modelica.Constants.eps; input SI.SpecificHeatCapacityAtConstantPressure cp "specific heat capacity of fluid at constant pressure"; input SI.DynamicViscosity eta "dynamic viscosity of fluid"; input SI.ThermalConductivity lambda "thermal conductivity of fluid"; output SI.PrandtlNumber Pr "Prandtl number"; end PrandtlNumber;