Combustion Of Solid Propellant. Particle Erosion Conditions

During taking-off and maneuvering flight, the SRM using metallic additive will suffer high acceleration which could change the movement of particles inside the chamber, causing particles to aggregate highly in local part. High density two-phase flow formed by aggregated particles has a considerable effect on the operation of SRM. Under high acceleration, high density two-phase flow would collect and aggregate on the burning surface, affecting the burning mechanism of solid propellant straightly. Burning rate characteristics of solid propellant under particle eroding condition was studied, with experiments carried out under different particle concentration and eroding velocity for various propellants. Effect of particle concentration, eroding velocity and gas-phase flow velocity on the solid propellant burning rate was investigated, revealing the burning mechanism under eroding condition, which lay a foundation for establishing the burning rate predicting model. Major contents and conclusions achieved are listed as following:1. A real-time measurement method and corresponding equipment were developed utilizing x-ray real-time radiography technique (RTR) to measure the regression process of solid propellant. Parameters such as particle concentration, eroding velocity and gas-phase flow velocity can be adjusted by altering the structure design and operation condition.2. Three-dimension numerical simulation for the experiment device was carried out, obtaining the particle concentration, eroding velocity and gas-phase flow velocity under different eroding angle and adjustor diameter, which provide the reference for experiment results analysis and experiment device verification.3. Experimental investigation for two type of solid propellant (HTPB and NEPE) was taken out under different eroding condition, acquiring the real-time regression image of burning surface and the average burning rate at different location utilizing the digital image processing technique. Compared with the burning rate without erosion, the burning rate of HTPB and NEPE were increased obviously under the eroding condition. It shows that the burning rate of HTPB is much sensitive to particle erosion than that of NEPE.4. It shows that particle eroding velocity is the key factor responsible for burning rate increasing, while particle concentration and gas-phase flow velocity have minor effect on burning rate. Obvious dividing phenomena can be concluded for the effect of particle erosion on burning rate, showing unapparent effect on burning rate with the...