预混煤油/空气两相旋转爆轰传播特性数值研究

Numerical study on propagation characteristics of two-phase rotating detonation of premixed kerosene/air

为研究预混煤油/空气两相旋转爆轰波的传播特性,以煤油蒸气/液滴为燃料,空气为氧化剂,开展了二维旋转爆轰过程的数值模拟计算,研究了气态燃料当量比和液滴直径对气液两相旋转爆轰过程中流场结构、胞格形状和数目、爆轰分数以及传播速度等特征的影响。结果表明:较高的气态燃料当量比和较小的液滴直径有利于旋转爆轰波的成功传播。气态燃料当量比为0.83时,可起爆的液滴直径增大至40μm。研究发现,爆轰波成功起爆的前提下,提高气态燃料当量比或减小液滴直径均利于胞格数目的增多和平均尺寸的减小,胞格数目为5.0~6.7,低于5.0爆轰波将无法维持传播;燃料的爆轰分数与气态燃料当量比和液滴直径有关,提高气态燃料当量比或减小液滴直径均促进燃料的爆轰分数以及爆轰波传播速度的提高,爆轰分数最高可达94.9%,爆轰波的传播速度为1 638.34~1 777.62 m/s,速度亏损在13%以内。

To study the propagation characteristics of premixed kerosene/air two-phase rotating detonation waves,numerical simulation calculations of two-dimensional rotating detonation processes were carried out using kerosene vapor/droplet as fuel and air as oxidant.The effects of gas-fuel equivalence ratio and droplet diameter on the characteristics of the flow field structure,cell shape and number,detonation fraction,and propagation velocity of the gas-liquid two-phase rotating detonation process were investigated.The results show that a higher gas-fuel equivalence ratio and a smaller droplet diameter are beneficial to the successful propagation of rotating detonation waves.When the gas-fuel equivalence ratio is 0.83,the diameter of the droplet that can be detonated can increase to 40μm.Under the premise of successful detonation,increasing the gas-fuel equivalence ratio or decreasing the droplet diameter is conducive to the increase in the number of cell and the decrease in the average size.The cell number is 5.0~6.7,and the propagation of the detonation wave will not be maintained below 5.0.The detonation fraction of fuel is related to the gas-fuel equivalence ratio and droplet diameter,increasing the gas-fuel equivalence ratio or decreasing the droplet diameter will increase the fuel’s detonation fraction as well the propagation velocity of the detonation wave.The highest detonation fraction can reach 94.9%,and the propagation velocity of detonation waves is 1638.34~1777.62 m/s,with a velocity deficit of less than 13%.