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MoistAir isentropicExponent() and specificEntropy() #4784

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MoistAir isentropicExponent() and specificEntropy() #4784

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9bfb31b
isentropicExponent assert
RaphaelGebhart Apr 29, 2026
69d1c26
specificEntropy assert
RaphaelGebhart Apr 29, 2026
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7 changes: 6 additions & 1 deletion Modelica/Media/Air/MoistAir.mo
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Original file line number Diff line number Diff line change
Expand Up @@ -877,7 +877,10 @@ Derivative function for <a href=\"modelica://Modelica.Media.Air.MoistAir.h_pTX\"

redeclare function extends isentropicExponent
"Return isentropic exponent (only for gas fraction!)"
protected
MassFraction Xsat = Xsaturation(state) "Water mass fraction at saturation";
algorithm
assert(state.X[Water] < 0.999*Xsat, "MoistAir.isentropicExponent() is invalid for saturated or supersaturated air; may yield grossly incorrect values (kappa = 3 instead of kappa = 1.4)", level = AssertionLevel.warning);
gamma := specificHeatCapacityCp(state)/specificHeatCapacityCv(state);
end isentropicExponent;

Expand Down Expand Up @@ -1050,8 +1053,10 @@ Derivative function for <a href=\"modelica://Modelica.Media.Air.MoistAir.specifi

redeclare function extends specificEntropy
"Return specific entropy from thermodynamic state record, only valid for phi<1"

protected
MassFraction Xsat = Xsaturation(state) "Water mass fraction at saturation";
algorithm
assert(state.X[Water] <= Xsat, "MoistAir.specificEntropy() is formally defined for unsaturated air; in supersaturated states results remain continuous but may exhibit deviations", level = AssertionLevel.warning);
s := s_pTX(
state.p,
state.T,
Expand Down