Direct numerical simulation of triple flame with different mixture concentration gradient
1. Institute for Energy Research, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Abstract： The direct numerical simulation（DNS）calculation of triple flame was carried out with detailed mechanism. Six cases with inlet width of 5，10，15，20，25 and 30 mm were respectively calculated under the condition that the range of equivalent ratio of mixture stayed the same. The results show that with the increasing of width，the mixture concentration gradient is decreased, and the thickness of triple flame is gradually increased with enhanced premixed flame branches. At the same time, the —OH mass fraction between triple point and premixed branches is gradually increased, while the —OH mass fraction at the branch of diffusion flame is gradually decreased. Since the range of the equivalent ratio of the inlet mixture remains unchanged, the premixed flame thickness hardly changes with the width. The flame velocity of the triple point has the maximum value in the mixture concentration gradient range from 0.051 1 to 0.295 0 mm-1.
