Solid Rocket Motor Plume Condensed Phase Particle Analysis Research

Condensed phase particles of plume flows in propellants are one of the major causes of smog and other signal characteristics. According to analysis, the main components of condensed phase particles were unburned carbon, metallic oxide particles, particles from coating layer and condensed water droplets. The size and concentration of smoke particles affects the capacity of penetration for a variety of optical signals, and the rate of smoke diffusion, thus the signal of guided weapon systems will be attenuated. Therefore, researchers have proposed different ways to carry out analysis condensed phase particles of plume flows in a solid rocket motor.The current collection and/or measurement methods for condensed phase particles of plume flows include mechanical method and photoelectric method. Mechanical method refers to collecting/measuring condensed phase particles by conventional mechanical contacting ways; photoelectric method refers to monitoring condensedphase optical particles by optical scattering or high-speed photography or other methods, without actually touching the coagulation phase particles.Condensed phase particles of plume flows in Solid rocket motors are of great significance to the performance of smoke signals and combustion performance test. In order to analyze the distribution of coagulation phase particles in solid rocket motor, we carried out a wide range of theoretical and experimental researches, the main research works are listed as follows:1. The main problem of mechanical measurement for condensed phase particle size distribution in solid rocket motor is the change of flow field structure and particle state, leading to state difference between collected particles and actual ones of the plume. In order to catch particle size distribution and capture the presence of small particles in real plume state, without destroying the structure of flow field, for measurements both by photoelectric and mechanical methods, we designed a multistage filter collection/measurement system. The experimental measurements were carried out with the device, and the results were obtained by analyzing the data of laser particle size.2. Based on Malvern analyzer for laser particle size, SPRAYTEC designed a realtime monitoring system for condensed particles in plume flow, and used the system for real-time particle size distribution measurement in plume stream of a solid rocket motor. The size distribution data of coagulation phase particles in plume flow of a solid rocket motor was obtained. The particle size of products showed a multi peak distribution, with a range of 10~250(μm). These results provided relevant data support for further analysis of plume signal and combustion characteristics.3. Using CFD software – FLUENT, with a certain type of attitude and orbit state solid rocket engine as prototype, we conducted simulations of gases with coagulation phase particles through the nozzle into cavity with multi-stage filter. The simulation of filter screen was achieved through porous media, and the working process of the multistage filter collection device was simulated and analyzed.