정적 연소실내 3차원 난류예혼합 화염 전파의 통계적 시뮬레이션

Abstract

A numerical technique to simulate the three dimensional propagation of turbulent premixed flames is presented. The objective is to further develop the existing two dimensional method and test the validity of the resulting technique in predicting the propagation speed and geometric structure of the flame. The approach uses time-series simulation of the unburned gas turbulence properties, such as mean velocity field, turbulence intensities, spatial and temporal correlations of velocity fluctuations. Influence of approaching flame on these properties were neglected. The dynamic behavior of the flame front was described by solving G-equation in an instantaneoulsly simulated turbulent flow field. Predictions were compared with existing experimental data and two dimensional simulations of hydrogen/air premixed flames with various turbulence intensities in a closed vessel. Three dimensional time dependent simulation resulted in correct trends of the measured flame data with increased accuracy compared with two dimensional simulation. Comparisons were made in flame radius growth rate, rms flame radius fluctuations, and average perimeter and fractal dimensions of the flame boundaries. The reasonable behavior and high efficiency proves the usefulness of this method in practical problems of flame propagation.