make pressure depend only on a_res

ClapeyronThermo · Sep 30, 2024 · 589656e · 589656e
1 parent 8f64900
commit 589656e
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 5 deletions.
diff --git a/src/methods/VT.jl b/src/methods/VT.jl
@@ -364,5 +364,7 @@ function VT_fugacity_coefficient!(φ,model::EoSModel,V,T,z=SA[1.],p = pressure(m
  return φ
 end
 
-export second_virial_coefficient,pressure,cross_second_virial,equivol_cross_second_virial
+export pressure
+export second_virial_coefficient,cross_second_virial,equivol_cross_second_virial
+
 
diff --git a/src/methods/differentials.jl b/src/methods/differentials.jl
@@ -16,14 +16,14 @@ function ∂f∂T(model,V,T,z=SA[1.0])
 end
 
 """
- ∂f∂V(model,V,T,z=SA[1.0])
+ ∂f∂V(model,V,T,z)
 
 returns `f` and `∂f/∂V` at constant temperature and composition, where f is the total helmholtz energy, given by `eos(model,V,T,z)`, and V is the total volume
-
 """
 function ∂f∂V(model,V,T,z)
- f(∂V) = eos(model,∂V,T,z)
- return Solvers.derivative(f,V)
+ f(∂V) = a_res(model,∂V,T,z)
+ dadv = Solvers.derivative(f,V)
+ return Rgas(model)*T*(dadv - sum(z)/V)
 end
 
 #returns a tuple of the form ([∂f∂V,∂f∂T],f),using the least amount of computation