COMPUTATIONAL ANALYSIS OF REACTION RATE IN AIR-METHANE STOICHIOMETRIC COMBUSTION

The reaction rate is defined as being the number of molecules of a reacting substance which reacts with another substance in time, this number being proportional to the product of reactors' concentrations. Advances in Computational Fluid Dynamics techniques provide nowadays the possibility to reach very high reaction rates in computational simulations, such as the ones which define the explosion type phenomena. At the same time, it is possible to determine with high precision the empirical coefficients used, so that after the dimensional analysis the physical and virtual sizes of the same entity, measured in homologous points, to lead to a more complete similarity. This paper deals with the computational analysis of air-methane stoichiometric mixture explosions, so that to establish the possibilities for handling the pre-exponential factor, the temperature exponent and the coefficients of the order of reaction from the reaction rate formulae developed by Arrhenius in 1889. During the simulation is monitored the reaction rate constant "k" which depends on temperature, on the pre-exponential factor, on the temperature exponent, and also on the ignition energy. It is afterwards analyzed along with the order of reaction coefficients as exponents of reacting substances concentrations, so that to determine their influence upon the reaction rate. Computational simulations are conducted using ANSYS Fluent.