Simulation of premixed combustion and near wall flame quenching in spark ignition engines with an improved formulation of the Bray-Moss-Libby model

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.

Theoretical and experimental based modifications have been investigated, such that the BML model can be applied to wall-bounded combustion modelling eliminating the wall flame acceleration problem. Estimation of integral length scale of turbulence has been made dynamic so that allowance for spatial inhomogeneity of turbulence is made. A new dynamic formulation has been proposed based on the Kolmogorov- Petrovski-Piskunov analysis and fractal geometry to evaluate the mean flame wrinkling scale. In addition, a novel empirical correlation to quantify the quenching rates in the influenced zone of the quenching region near solid boundaries has been derived based on experimentally estimated flame image data. The proposed model was then applied to simulate the premixed combustion in spark ignition engines. Full cycle combustion in a Ricardo E6 engine for different operating conditions was simulated. Results show that the present improvements have been successful in eliminating the wall flame acceleration problem, while accurately predicting the in- cylinder pressure rise.