爆燃脉冲发动机内弹道模拟及实验分析

Simulation and Experimental Analysis of Interior Ballistics of Deflagration Pulse Rocket

关键词:  固体冲量发动机  微气孔球形推进剂  喉燃比  对流爆燃  点火内弹道

Key words:  Solid impulse-rocket  Micropore ball powder  Throat-to-burning surface ratio  Convective deflagration  Ignition interior ballistic

摘要:

为了研究质量轻便、结构紧凑的固体冲量发动机，提出以微气孔球形推进剂作为能量材、以对流爆燃形成高内压为模式的脉冲动力方案。通过分析不同推进剂密度、长度、点火药量和膜片形式等因素，得到了大喉燃比发动机中球形装药爆燃诱导条件；根据球形装药爆燃特性，通过数值模型研究了新型爆燃冲量发动机的内弹道与流场特性。结果表明：装药长度、装药密度和点火药量均对发动机中爆燃现象的出现有明显影响，较长装药、较小装药密度和较大点火药量均利于诱发对流爆燃；微气孔球形药在发动机燃烧室内燃速与压力规律以分段的指数燃速形式出现；初步论证了一体式爆燃脉冲发动机的实用潜力。

Abstract:

In order to study the lightweight and compact impulse solid rocket motor， a new integrated impulse-rocket solution was proposed， which uses the ball powder with micropores as the energy material and builds the high-pressure internal ballistic by inducing convective deflagration of grain. By analyzing grain density， grain length， ignition charge， and diaphragm form， the deflagration induction conditions of the ball powder with micropores were obtained in the rocket with a large throat-to-burning surface ratio. Based on the deflagration characteristics of the ball powder with micropores， the trajectory and flow field characteristics of the new integrated impulse rocket were both demonstrated. The results show that the grain length， the grain density， and the amount of ignition charge all have a significant effect on the appearance of the deflagration， the longer grain length， the smaller grain density and the larger amount of ignition charge are beneficial to inducing convective deflagration. In the chamber of the rocket， the dependence of the micropore ball powder’ burning rate on local static pressure over a useful range of pressures is governed by segmented exponential burning rate. It is preliminarily demonstrated that the possibility of high-pressure operation of the new impulse-rocket.