Equations for the Lee-Kesler equation of state

The following equation gives the compressibility factor for a fluid that uses the Lee-Kesler (LK) equation of state (EOS):

where

w is the general acentric factor

wr is the acentric factor of the reference fluid (n-octane), a constant quantity of 0.3978

Z is the general compressibility factor

Zs is the compressibility factor of the simple fluid

Zr is the compressibility factor of the reference fluid

The LK EOS calculates the compressibility factor for the simple and reference fluids based on the Benedict-Webb-Rubin (BWR) equation developed in 1940[3]:

where

b, g, bi, ci, and di are all constants whose values depend on the type of fluid

The LK EOS uses the following twelve constants for the simple fluid and reference fluid.