管道内运动火焰生成压力波及其特性的研究

Study on Properties of Pressure Waves Generated by Steady Flames in a Duct

从一维非定常守恒方程出发 ,本文用Richtmyer Lax Wendroff格式研究了压缩波、稀疏波、燃烧速率、火焰熄灭和管道长度对管内运动火焰生成压力波的影响 .结果表明 :相对于火焰面 ,同向压力波和异向稀疏波会加速火焰传播 ;异向压力波和同向稀疏波使火焰传播减速 ;增大燃烧速率使得和火焰面两侧的压力、温度增大 ;火焰熄灭时 ,火焰面变为接触间断面 ,同时产生稀疏波向火焰面两侧传播 .此后 ,接触间断面几乎处于滞止状态 ;增加管子长度会促使燃烧向爆轰转变 .

One dimensional unsteady equations and Richtmyer Lax Wendroff scheme were used to study the influences of compression and rarefaction waves, combustion speed, flame out and length of tube to the pressure waves generated by steady propagating flames. The results indicate that the traveling flames are accelerated by compression waves traveling in the same direction or rarefaction waves traveling in the opposite direction with respect to the flame front. Otherwise, flames are decelerated. Increasing combustion speed increases the pressure and temperature on both sides of the flame front. The flame front is transformed into an interface as soon as the flame is extinguished, and the interface is almost stopped. Also, the rarefaction waves propagates into the unburned and burned gases. Increased tube length will contribute to the deflagration to detonation transition.