Fix where the Rratio is applied for GERG

Appears to be correct in GERG-2008 and not in GERG-2004
usnistgov · Mar 17, 2024 · 441867a · 441867a
1 parent 4312b0b
commit 441867a
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/include/teqp/models/GERG/GERG.hpp b/include/teqp/models/GERG/GERG.hpp
@@ -357,12 +357,12 @@ class GERG200XAlphaig{
         const std::vector<double>& theta0i = c.theta0;
         using std::abs;
         double Tci = Tc[i];
-        auto out = forceeval(log(rhomolar/rhoc[i]) + n0i[1] + n0i[1]*Tci/T+ n0i[3]*log(Tci/T));
+        auto out = forceeval(n0i[1] + n0i[1]*Tci/T+ n0i[3]*log(Tci/T));
         if (theta0i[4] != 0) { out += n0i[4]*log(abs(sinh(theta0i[4]*Tci/T))); }
         if (theta0i[6] != 0) { out += n0i[6]*log(abs(sinh(theta0i[6]*Tci/T))); }
         if (theta0i[5] != 0) { out -= n0i[5]*log(abs(cosh(theta0i[5]*Tci/T))); }
         if (theta0i[7] != 0) { out -= n0i[7]*log(abs(cosh(theta0i[7]*Tci/T))); }
-        return forceeval(Rstar/R*out);
+        return forceeval(log(rhomolar/rhoc[i]) + Rstar/R*out); // Note that the GERG-2004 manuscript has the wrong location for the ratio Rstar/R and the GERG-2008 manuscript is correct
     }
 
     template<typename TType, typename RhoType, typename MoleFractions>