private subroutine solve_point_psat(model, ncomp, nc, X, ns, S, F, dF, dFdS, its)

Solve point

Solve a saturation point for a pure component.

Description

The set of equations to solve is:

$$\begin{align*} f_1 &= \ln f_{z}(V_z, T) - \ln f_{y}(V_y, T) \\ f_2 &= \ln \left( \frac{P_z}{P_y} \right) \\ f_3 &= \ln P_z - \ln P \\ f_4 &= g(X, ns) \end{align*}$$

Where $f_4$ is an specification function defined as:

$$g(X, ns) = \left\{ \begin{array}{lr} \ln \left( \frac{V_z}{V_y} \right) - S & \text{if } ns = 1 \text{ or } ns = 2 \\ X(ns) - S & \text{otherwise} \end{array} \right\}$$

The vector of variables $X$ is equal to $[ \ln V_z, \ln V_y, \ln P, \ln T ]$.

Arguments