A method of calculating of the thermodynamic properties and the composition of the explosion products of hydrocarbons and air under partial chemical equilibrium

We examined the approximate method to calculate composition and thermodynamic parameters of hydrocarbons air nonequilibrium explosion products based on the assumption of the existence of a partial chemical equilibrium. With excellent accuracy of calculating thermodynamic properties and species mass fraction the respective stiff system of detailed kinetics differential equations can be replaced by the one differential equation or the two differential equations and a system of algebraic equations. This method is always consistent with the detailed kinetic mechanism. The constituent equations of the method were derived and the respective computer code written. We examine the applicability of the method by solving the test problem. The proposed method simulation results are in excellent agreement with the detailed kinetics model results corresponding the stiff ordinary differential equation solver including NO time histories.