Part 1. General problems of the intellectual systems theory

Numerical solution of the multiparameter Benedict-Webb-Rubin equation of state with high accuracy

E. V. Koldoba

Lomonosov Moscow State University, Faculty of Mechanics and Mathematics

Abstract: When solving the nonlinear Benedict-Webb-Rubin equation, Newton’s method is usually used. In some areas of pressure and temperature, the equation has many roots; to find the root we need, we must carefully set the initial values for Newton’s method. To do this, it is proposed to use formulas that specify the densities of the gas and liquid phases at the equilibrium gas-liquid phase transition, which can be adjusted to the equation being solved. This approach makes it possible to construct a thermodynamically consistent model convenient for numerical solution, which increases the reliability of calculations.

Keywords: numerical algorithms, multiparameter equation of state, Benedict-Webb-Rubin equation