Experimental Investigation of Initial Pressure Rise with Igniter Charge Mass in Single Grain Rocket Motor

Abstract

In the present research work, the effect of the igniter charge mass on the initial pressure rise in single grain solid propellant rocket motor is investigated experimentally. The igniter in the rocket motor is used to ignite propellant in rocket motor. Experiments are done with varying igniter charge mass by approximately ±15% of the calculated igniter charge mass value i.e. ~35g. Maximum pressure noted at 35g calculated igniter charge mass is 8.5632 MPa. Various experiments with 25g, 30g, 40g and 45g of igniter charge mass is carried out to study the effect of igniter charge mass on maximum pressure in rocket motor keeping all other parameters i.e. nozzle throat diameter, nozzle end grid, head end grid etc. are kept same. For each igniter charge mass two static tests were conducted. As igniter charge mass is increased from 25g to 45g ignition transient pressure increased from 2.9 MPa to 5.65 MPa, by optimizing the igniter charge mass the initial pressure can be kept within required range of MEOP (Maximum Expected Operating Pressure) for safe working of rocket motor.