Monte carlo computation of turbulent premixed methane-air ignition

A one-dimensional time dependent monte Carlo numerical computation of sparkignited premixed flames propagating in isotropic turbulence is described. The Monte Carlo method is a statistical fluid particle tracking method for modeling turbulence. The presumed method uses the probability distribution function (PDF) method in order to avoid full solution of the flow equations. The model simulates flame propagation in a homogenous, turbulent environment by prescribing Gaussian distributions of the PDFs of fluctuating velocity and fuel concentration. The current model is unique in that it does not require the modeling of complex chemistry or sophisticated, and costly, flow solvers. Solutions have been obtained for the early phase spark ignition of a lean gaseous mixture of methane-air in a turbulent, spherically-symmetric environment. The simple, yet robust, Monte Carlo method correctly predicts such trends as the increase in turbulent flame propagation speed with increasing turbulence intensity. Turbulent flame speeds are in good agreement with experimental and numerical values reported in the literature. An expression correlating the turbulent flame speed and the rate of speed fluctuations compares well with correlations of other researchers.