Design And Performance Test Of Impulse Thruster

Impulsive thrusters are more and more widely used in aerospace, military, etc for its simple structure and large output thrust in milliseconds. An impulsive thruster of which the action time was less and the output thrust was large was designed base on the inquiry and the principle of solid rocket engine. The nozzle throats with different diameter and the jet-pipe with different number of nozzles were designed.The main charge has great effect on output characteristic of the thruster. In order to design the best main charge, NH4ClO4 and RDX were chosen as the oxidizer and Al was chosen an the fuel.NC was chosen as the binder. Six different formulations were chosen and their detonation heat, explosion temperature, specific volume and explosive force were calculate In theory. When the formulations which contained RDX used as the main charge in the thruster, the main charge case would be destroyed, so it would not be used. The other three formulations and six different powders were tested by closed bomb measurement method. The consequence was that duo45 and the third formulation had less action time and produced more gas, so they could be uses as the main charge.Different main charges, varying charge weight, different nozzle throat diameter were measured by testing system built. The test result indicated that the third formulation produced more thrust and specific impulse than duo 45; output thrust and impulse increased as charge mount is increased; increasing nozzle throat diameter could cause obvious decreases of both the thrust and impulse; more number of nozzles decreased the thrust and extended the action time but increased the total impulse.When two thrusters were ignited together, the ignition delay time was much less using BK as the igniting charge than using black powder.Numerical analysis of thrusters with one nozzle and four nozzles was carried out, the profiles of pressure and Mach number was obtained by the computation. The computed results of output thrust were compared with measured value.