dT/dp along saturation: protect against division by zero

modelica-3rdparty · May 3, 2020 · 797d72d · 797d72d
1 parent 89c6b9b
commit 797d72d
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/HelmholtzMedia/Interfaces/PartialHelmholtzMedium/package.mo b/HelmholtzMedia/Interfaces/PartialHelmholtzMedium/package.mo
@@ -1664,8 +1664,9 @@ protected
   output DerTemperatureByPressure dTp;
 
   algorithm
+    assert(sat.vap.s<>sat.liq.s, "liq and vap entropy identical", level=AssertionLevel.warning);
     // Clausius-Clapeyron equation
-    dTp := (1.0/sat.vap.d-1.0/sat.liq.d)/(sat.vap.s-sat.liq.s);
+    dTp := (1.0/sat.vap.d-1.0/sat.liq.d)/max(Modelica.Constants.eps, (sat.vap.s-sat.liq.s));
   annotation(Inline = true);
   end saturationTemperature_derp_sat;