lib.PRMelhem module

class lib.EoS.Cubic.PRMelhem.PRMelhem(T, P, mezcla, **kwargs)[source]

Bases: PR

Peng-Robinson cubic equation of state with a modified dependence of temperature by Melhem

\[\alpha = \exp\left(m\left(1-T_r\right) + n \left(1-\sqrt{T_r}\right)^2\right)\]

where n and m are adjustable parameters compound specific

_alfa(cmp, T)[source]

α parameter calculation procedure, separate of general procedure to let define derived equation where only change this term like the 1978 version.

This method use the original alpha formulation for temperatures below the critical temperature and the Boston-Mathias formulation for supercritical states.

The procedure return too the m parameters because it’s used in Helmholtz formulation

Parameters:
cmpcomponente.Componente

Componente instance

Tfloat

Temperature, [K]

Returns:
mfloat

m parameter of equation, [-]

alphafloat

Correlation for alpha expresion at supercritical temperatures: * 0 - Original * 1 - Boston-Mathias

References