Solid Propellant Micromotors and Impulsive Thrusters

Light weight solid propellant motors which supply high thrusts (>500 lbf) for durations on the order 0.010 sec. (referred to as impulsive thrusters) require special analysis of items such as internal ballistics, propellant combustion, ignition stimuli, and inert hardware. An almost explosive ignition and pressurization coupled with the requirements for reproducible thrust versus time programs are analyzed by a mathematical model that emphasizes gas flow and propellant combustion dynamics. To further reduce impulsive thruster operating times, limitations in propellant burning rate must be circumvented by departures from conventional internal burning, thin propellant web motor designs. A novel approach that uses a dense, porous propellant is described in terms of a recently developed combustion theory for porous propellants.