固体推进剂燃速的超声波测量

为了实时测量固体推进剂燃速与燃烧室压强的关系,利用超声波数据采集卡搭建了超声波实时燃速测量系统,通过调节点火药量和密闭燃烧器容积可以调节密闭燃烧器的压强范围.经过实验得到了低压范围内的实时燃速数据以及燃速与压强的对应关系.结果表明,利用超声波燃速测量系统可以一次性获得给定压强范围内的实时燃速;燃面附近的高温层会使厚度测量值偏小,对燃速测量没有影响;在点火初期,燃面高温层建立的非稳态过程影响超声波声速;在接近试件燃尽的时刻,推进剂两个端面的回波信号产生干扰.

Ultrasonic Technique for Burning Rate Measurement of Solid Propellant

A burning rate measurement system based on the ultrasonic technique is established for solid propellant.The range of pressure can be adjusted by changing the mass of ignition powder and the volume of combustor.Based on the experiment,real-time burning rate of a composite propellant is measured under lower pressure,and the relation between burning rate and pressure is obtained through data processing.The burning rate of solid propellant within certain pressure range can be obtained.By using ultrasonic measurement system the high-temperature layer on burning surface has negative effect on thickness measurement but neglectable effect on burning rate measurement.In the ignition period,the unstable establishment process of high temperature thin layer affects the sound speed.And in the burning out period of the test sample,the echo pulses of both the burning surface and the couple material interface meet and interfere each other.