电火花点火和激光点火性能对比研究

为了比较激光点火和电火花点火的点火性能,在一带稳定器方形直管试验段上,利用电火花调能调频点火器和激光器分别进行点火试验,比较相同来流条件下的初始火核发展、点火极限和火焰传播。结果表明:两者的初始火核形状不同,电火花点火的初始火核呈圆弧形,而激光点火下呈瓣型。相同点火能量下,激光点火比电火花点火的贫油点火极限更宽;相同来流条件下,点火位置下游激光点火的火焰传播速度更快,并且在化学恰当比附近和来流速度为2.14m/s的情况下,两种点火模式的火焰传播速度相差更大。

Comparative Study of Spark Ignition and Laser Ignition Performance

To compare the ignition performance of electric spark and laser induced spark ignition, experiments are carried out by using a modulated electric spark plug and a laser. The evolution of initial flame-kernel, ignition limits and flame propagation speed of these two different ignition modes are compared and analyzed under the same flow condition. The results show different shapes of the two initial flame kernels. The initial flame kernel of spark ignition is arc-shaped while laser ignition is petal shaped. Laser ignition has wider lean ignition limit than spark ignition within the same ignition energy. Flame propagation of laser ignition behind ignition position is faster than that of spark ignition under the same flow condition. Meanwhile, the differences of flame propagation speed between these two ignition patterns are much larger around stoichiometric ratio and at the flow velocity of 2.14 m/s.