障碍物和管壁导致火焰加速的三维数值模拟

Numerical Investigation on Three-dimensional Flame Acceleration Induced by an Obstacle and Tube Internal Walls

基于K ε模型和改进的EBU Arrehnius燃烧模型 ,考虑了障碍物对流动的附加作用 ,通过修改方程的源项 ,建立了湍流加速火焰现象的理论模型。选用Simple格式 ,壁面边界层采用壁面函数法处理 ,模拟了障碍物和摩擦管壁在三维空间中导致火焰加速的现象 ,结果表明障碍物和管壁对火焰都有明显的加速作用 ,且障碍物的加速作用更明显 。

Based on k-Ε turbulence model and an improved EBU-Arrhenius combustion model, the theoretical model of flame acceleration by turbulence is established by modifying the source term in the equations. The additional influence of obstacle is considered. SIMPLE algorithm is adopted to solve the governing equations. The wall-function is chosen to deal with the boundary near the wall. The phenomena that flame is accelerated by an obstacle and tube wall are investigated numerically. The results show that both obstacles and tube internal wall could accelerate the flame. The acceleration effect by an obstacle is more obvious. The mechanism of flame acceleration is explored too.