Study On Working Process Of DT-3 Gelled Monopropellant Thrusters

Gel propellant is a new type of rocket engine propellant. They have good development and application prospects in the future in the field of Aeronautics and Astronautics for they have both the advantages of solid propellant and liquid propellant. Based on this background, the linear stability analysis and the working process’s numerical simulation of DT-3 gelled propellant in the combustion chamber have been carried out.A temporal stability analysis has been carried out to model the breakup of a power-law liquid jet. The dispersion relation of a power-law liquid jet is obtained by integrating the axisymmetric governing equations for the power-law liquid jet. The investigation shows that the maximum growth rate and the dominant wave number increase with the increase of the relative velocity and gas dynamic viscosity, while they both decrease as the liquid surface tension, liquid jet radius, air boundary layer, and power-law index increase. Therefore, changing the corresponding conditions will improve the instability of the liquid jet and be advantageous for the breakup of the liquid jet. Jet experiment system is set up. The largest perturbation wave length of the experimental results and the theoretical calculation results are compared. It is found that, although the results have some differences, but with the increase of jet velocity, the difference gradually decreases.The simulations to the different parameters were carried out by using the Fluent software. A sensitivity study for the effect of the thruster parameters on the pressure, temperature, and species concentration distributions of the reactor has been conducted. The results obtained from the numerical simulation show that the chamber temperature and pressure increase with a shorter catalyst bed, due to a lower ammonia dissociation rate. Keeping the length of the catalytic bed as well as the pressure constant, ammonia dissociation decrease as the propellant flow rate increase. With the propellant temperature increasing, ammonia decomposition rate will be slightly increased, the combustion chamber pressure and temperature will be slightly decreased. The decrease of the porosity of the porous medium will increase the pressure loss of the catalytic bed, thus reducing the temperature of the combustion chamber. The results also reveal that the interaction between hydrazine and the catalyst bed, such as the liquid permeability, has significant influences on the reaction characteristics.