Mixing and chemical reacting flow simulations inside square cavities

Abstract

The aim of this work is the numerical solution of laminar flows inside a square cavity caused by temperature increase due to a chemical reaction. The model approximates the overall, single step, binary, irreversible reaction between two species, resulting in a third, which is taken to be a process of first order with respect to each of the reactants, where the specific reaction rate is controlled by temperature-dependent Arrhenius kinetics. The simulations are performed using the finite differences explicit Runge–Kutta three-stage scheme for second order time and space approximations. Consistent results, for reactant and product concentration fields, as well as for temperature of reaction, are obtained, showing that the model is able to follow nonlinear behavior of the mixing and reaction progress, for Schmidt and Prandtl numbers of order 1, Zel'dovich 5, Damköhler 300 and heat release parameter ranging from 300 to 1000, which are values for high temperature gaseous hydrocarbon chemistry. Besides, it is worth pointing out that these results build on earlier ones, which were obtained from thin-layer model approximations.