Rayleigh–Benard convection in a chemical equilibrium gas (simulation of surface detonation wave initiation)

The problem of the Rayleigh–Benard convection for a chemical equilibrium gas is solved numerically. The gas is assumed to be incompressible, and the layer boundaries are assumed to be flat, isothermal, and free from shear stress. The Boussinesq model with the coefficient at the buoyancy term depending on the transverse coordinate is used. The resultant nonlinear system of equations is solved by a previously developed numerical method based on the spectral representation of vorticity and temperature fields. According to the idea of splitting, analytical formulas are first used to take into account the linear increase in disturbances, and then the nonlinear convective transfer is calculated by the finite-difference method. Various convection modes are obtained: stationary, periodic, quasi-periodic, and stochastic convection.The model of convection of a chemical equilibrium gas, presented here, can be useful for the understanding of the transition of a cellular combustion of surface systems into an explosion (initiation of surface detonation) and for the calculation of operating regimes of chemical reactors.