快速增压条件下的复合推进剂动态形变测量(英文)

Dynamic impact deformation of composite propellant under rapid pressurization using high-speed camera

针对发动机内固体推进剂在快速增压条件下的形变现象,设计了一套冷流实验测量装置,利用高速摄影机进行动态拍摄,获得了不同压强冲击条件下的推进剂动态形变数据。结果表明,推进剂形变大小与推进剂两端的压强差有很大关系,压强差越大,推进剂形变越大。同时,推进剂形变的速率与推进剂形变大小也有一定的关系,形变越大,相应的形变速率越小。分析认为,这一现象与推进剂的非线性粘弹性有很大关系。

To understand the operational process in a combustion chamber, the main factor governing the interior phenomena of the SRM is the flow of high pressure gases. For the structural integrity evaluation of solid propellant grains under rapid pressurization load, a small SRM tester was designed to follow the deformation of the propellant under cold flow conditions, to investigate the visco- elastic nature of the propellant. Here the pressurization is created by a gas supply system using nitrogen gas, high-speed camera is used to record the data, which is used then to convert these data into displacement vector and strain rate. Two pressure transducers were used to measure the pressure in the head-end and the aft-end of the tester. Results show that during this test deformation is de- tected and pressure difference along the tester is measured, the data acquisition system shows two different pressurization curves. The deformation is dependent on the pressure difference and increases with this difference;we successfully measure the strain rate for each test. When the deformation is smaller the strain rate is higher, and when the deformation is larger, the strain rate is smaller which could be interpreted by the nonlinear viscoelastic behavior of the propellant.