Implementation of Net-Event Monte Carlo algorithm in chemical kinetics simulation software of complex isothermal reacting systems

Abstract

Many stochastic methods are available for kinetic simulation of a spatially homogeneous chemical or biochemical reacting system. These methods become time costing for very complex systems with huge mechanism as in combustion reactions or even with moderate mechanism with stiffness. In this work, a new algorithm based on Net-Event Kinetic Monte Carlo (NEKMC) method is implemented to improve the Kinetic Monte Carlo (KMC) method of simulation by reducing the calculation time. A set of N reversible reactions, in a given mechanism, is considered as 2N elementary reactions in the KMC method, but in the NEKMC method just N reactions are considered. For each reversible reaction, the net-probability can be calculated by using the absolute value of the difference between the rates of the forward and the reverse reaction. By doing this, the number of events is divided by two and should reduce consequently the calculation time. This new method (NEKMC) is described and tested on complex systems and speediness of the program is compared for this method to the old one (KMC).