PengRobinson78 Function

public function PengRobinson78(tc, pc, w, kij, lij) result(model)

PengRobinson78.

Using the critical constants setup the parameters to use the PengRobinson Equation of State

• $$\alpha(T_r) = (1 + k (1 - \sqrt{T_r}))^2$$
• $$k = 0.37464 + 1.54226 \omega - 0.26992 \omega^2 \text{ where } \omega <=0.491$$
• $$k = 0.37464 + 1.48503 \omega - 0.16442 \omega^2 + 0.016666 \omega^3 \text{ where } \omega > 0.491$$
• $$a_c = 0.45723553 R^2 T_c^2 / P_c$$
• $$b = 0.07779607r R T_c/P_c$$
• $$\delta_1 = 1 + \sqrt{2}$$
• $$\delta_2 = 1 - \sqrt{2}$$

There is also the optional posibility to include the $k_{ij}$ and $l_{ij}$ matrices. Using by default Classic Van der Waals mixing rules.

After setting up the model, it is possible to redefine either the mixing rule or the alpha function using a different derived type defined outside the function.

Arguments

Type	Intent	Optional	Attributes		Name
real(kind=pr),	intent(in)			::	tc(:)	Critical Temperatures [K]
real(kind=pr),	intent(in)			::	pc(:)	Critical Pressures [bar]
real(kind=pr),	intent(in)			::	w(:)	Acentric Factors
real(kind=pr),	intent(in),	optional		::	kij(:,:)	$k_{ij}$ matrix
real(kind=pr),	intent(in),	optional		::	lij(:,:)	$l_{ij}$ matrix

Return Value type(CubicEoS)

Variables

Type	Visibility	Attributes		Name		Initial
type(AlphaSoave),	private		::	alpha
type(Substances),	private		::	composition
integer,	private		::	i
type(QMR),	private		::	mixrule
integer,	private		::	nc