复合推进剂燃烧不稳定的压强耦合响应机理研究

The propellant combustion response is the primary source of Solid rocket combustion instability which can drive the acoustic oscillations in the combustion chamber and the pressure-coupled response is an important driver. We will use theoretical analysis, numerical simulation combining with experimental study to investigate the pressure-coupled response mechanism of composite propellant. The device to measure the prssure-coupled response of composite propellant is very important to investigate the propellant combustion response, and will be developed in this paper. Based on the T-burner, the pulser will be designed and double-pulsing test method will be adopted. Through adopting excellent method of numerical computation, we will develop the combustion micro-model and the method for predicting the pressure-coupled response. By studying the influence which be imposed on the pressure-coupled response by the propellant formulation, the operating pressure or the frequency of acoustic oscillations, and the response mechanism between the combustion in the gaseous phase and acoustic oscillations, the pressure-coupled response mechanism will be gained. The mechanism which be finded out will provide theoretical guidance for damping the combustion instability in the solid rocket motor.

固体发动机燃烧不稳定在燃烧室中的主要声能增益是推进剂的燃烧响应，而压强耦合响应是其主要体现形式。本项目将采用理论分析、数值模拟与实验研究相结合的方法，开展复合推进剂压强耦合响应机理研究。通过解决复合推进剂压力耦合响应测试和细观燃烧模型数值方法的关键技术，建立脉冲T型燃烧器压力耦合响应特性研究实验方法、复合推进剂细观燃烧模型及压强耦合响应预示方法，开展推进剂配方、工作压强及压强振荡频率对耦合响应的影响及敏感性分析和气相燃烧区域对压强振荡的响应机制研究，获得复合推进剂压强耦合响应影响规律，揭示压强耦合响应机理，为抑制固体发动机不稳定燃烧提供理论指导。

本项目基于外部脉冲激励的T型燃烧器测量技术，针对发动机中出现燃烧不稳定问题发动机采用的推进剂进行研究，通过调节推进剂配方分别获的了三种共16种配方的推进剂，对其进行响应函数测量，获得推进剂配方对响应函数影响的规律。实验结果表明，相同工况条件下，推进剂中的氧化剂AP粒子采用双级配的响应函数值明显小于采用单级配大尺度粗颗粒AP粒子的推进剂。AP粒子中随着粗粒度的含量增大，响应函数呈增大的趋势。同时，针对复合推进剂细观燃烧模型及压强耦合特性预估，成功的解决了复合推进剂压强耦合响应特性数值方法的关键技术，建立了AP粒度双级配的复合推进剂燃烧模型，针对其影响因素，获得了复合推进剂压强耦合响应影响规律，揭示了压强耦合响应机理，为抑制固体火箭发动机不稳定燃烧提供理论指导。该项目设计的T性燃烧器实验测量技术申请专利两项，并获得授权；同时其实验测量技术已经成功的应用到国内多家研究单位中，并形成研究所所标。