Derived Types

Abstract derived type that describe the required procedure for an alpha function.

Mathias Copeman $\alpha$ function.

RKPR $\alpha$ function $$\alpha(T_r) = \left(\frac{3}{2 + T_r}\right)^k$$

Soave $\alpha$ function. $\alpha(T_r) = (1 + k (1 - \sqrt{Tr}))^2$

Abstract residual Helmholtz model.

Base model type.

Enumerator to handle the possible specifications for a critical point.

This derived type is used to store a critical line between two fluids. The critical line is calculated using the critical_line function. It uses the continuation method.

Critical point

Critical point

Critical point

Generic Cubic Equation of State as defined by Michelsen and Mollerup with a $\delta_1$ parameter that is not constant, and a $\delta_2$ parameter that depends on it. In the case of a two parameter EoS like PengRobinson the $\delta_1$ is the same for all components so it can be considered as a constant instead of a variable. The expression of the Equation is:

Abstract derived type that describe the required procedure for a mixing rule on a Cubic EoS

Description of a two-phase equilibria state.

$G^E$ group contribution model parameters container

Excess Gibbs energy model.

Derived type used to represent a molecule and its UNIFAC groups.

Mixing rule at zero-pressure which allows for the inclusion of an excess-gibbs model.

Non-Random-Two-Liquid model

UNIFAC $\psi(T)$ functions abstract type

Two-phase isopleth. Phase boundary line of a fluid at constant composition.

Two-phase PX envelope. Phase boundary line of a fluid at constant temperature with variation in composition.

Quadratic Mixing Rule (QMR) derived type. Classic Van der Waals mixing rules.

Set of pure components

Two-phase TX envelope. Phase boundary line of a fluid at constant temperature with variation in composition.

Classic liquid-vapor UNIFAC model derived type

$$\psi_{ij}(T) = \exp(-\frac{A_{ij}}{T})$$

UNIQUAC (universal quasichemical) Excess Gibbs free energy model.