Numerical Simulation Analysis Of Aluminum Particle Flow In Low Pressure Generators

The solid rocket motor propellant with high aluminum content could not burn sufficiently in the combustion chamber, end up with high temperature gases including many incomplete combustion aluminum particles. These products will be on fire again once they come across the oxygen in the atmosphere, which will increase the temperature of the plume, and also affect the flow parameters of the plume. So it is necessary to have a research on the afterburning of such rocket motor plume.The combustion characteristics at low combustion pressure in exhaust plume of highly-aluminized propellant was studied through the establishment of three-dimensional Reynolds-averaged N-S equations and the standard κ-ε model by way of the computational fluid dynamics software(FLUENT). In the same time, the effects of aluminum diameters, combustion pressures, nozzle backpressures and propellant formulation on the plume afterburning had been investigated. And the experiments were carried out, too. The results showed that two high-temperature regions, two temperature peaks in other words, appear when aluminum are added into the plume. The first high-temperature region formed by the combustion of pure gas components is nearer to the nozzle, which is also called the gas high-temperature region. And the second one formed by the combustion of the aluminum further to the nozzle is called particle high-temperature region. The lower the pressure of the combustion chamber is, the closer the particle high-temperature region is to the nozzle, the gas high-temperature region no change. The smaller the aluminum particles are, the closer the particle high-temperature region is to the nozzle, the higher the temperature of the particle region. The particle high-temperature region will get further to the nozzle as the nozzle backpressure gets lower. The temperature of the gas high-temperature region gets higher as the ratio of AP/HTPB gets higher, while particle high-temperature region gets lower. When the value of OB gets higher, the particle high-temperature region will level off until it disappears. The results above are of accordance with that of experiment results.