激波对凹腔火焰稳定器流场影响

为揭示激波对超声速流中凹腔流场的影响规律,在超声速流中利用长9 mm,坡度为23°的斜坡产生激波。组合利用高速摄影仪和纹影仪,采用碘钨灯、连续激光和脉冲激光作为光源,摄像曝光时间分别为1 m s,8 us,8 ns,获得了斜坡激波入射在单个凹腔中部、中后部和后部,以及激波入射在不同构型凹腔相同位置的流场纹影图像。结果表明,凹腔自由剪切层在受到激波撞击后,在入射点前会发生弯曲而偏向主流,在入射点后加速发展和破碎;激波入射点靠近前沿则引起凹腔前沿激波的增强,靠近凹腔后沿导致再附激波减弱。

Effect of shock wave on flow in cavity flame holder

To investigation the effect of shock wave on flow in cavity flame holder,a 9mm long,23° angle wedge was adopted to simulate the wanted shock.The instantaneous flowfield with shock wave effect on the cavities in forehead,middle and rearward,and shock impinged at the same place of different cavities,with expose time of 1ms,8us,8ns was observed by high speed camera and schlieren system.The schilieren system took use of pulsed laser light,continuous laser light and Iodine-Tungsten light as light source.Results revealed that the free shear layer of cavity was distorted into the main flow before the shock impingement point,and quickly broken up behind the impingement position;the impingement position close to the front corner of cavity can lead to stronger shock while the position close to the back corner of cavity can decrease the reattachment shock.