APPLICATION OF FRONT TRACKING TECHNIQUES TO THE TURBULENT COMBUSTION PROCESSES IN A SINGLE STROKE DEVICE

A numerical model for the simulation of turbulent combustion processes has been developed that employs front tracking techniques originally designed for thin laminar flames and extents these techniques to turbu lent reaction zones of finite thickness. The main features of the mode l are a two dimensional calculation of the propagation of the combusti on zone and the pertinent flow field and a two-zone model for the temp erature, pressure and composition. For the turbulent burning velocity an expression is established which describes its development with time in the initial stage of combustion and its approach to a steady state value. The reaction zone thickness is modeled by an entrainment model which has been modified to be combined with the front tracking techni ques. The model is applied to the turbulent combustion process in a ra pid compression device which maintains the basic features of an intern al combustion engine. Results of the numerical simulation concerning f lame structure and propagation, burning function y(b)(t) and developme nt of pressure with time p(t) are given for different fuels, different levels of turbulence intensity and different compression ratios. The results agree satisfactorily with experimental data.