Solid propellant burn rate, propellant gas flow rate, and propellant gas pressure pulse generation control system and method

Abstract

Systems and methods of controlling solid propellant burn rate, propellant gas pressure, propellant gas pressure pulse shape, and propellant gas flow rate, rely on pulse width modulation of a control valve duty cycle. A control valve that is movable between a closed position and a full-open position is disposed downstream of, and in fluid communication with, a solid propellant gas generator. The solid propellant in the solid propellant gas generator is ignited, to thereby generate propellant gas. The control valve is moved between the closed position and the full-open position at an operating frequency and with a valve duty cycle. The valve duty cycle is the ratio of a time the control valve is in the full-open position to a time it takes the valve to complete one movement cycle at the operating frequency. The valve duty cycle is controlled to attain a desired solid propellant burn rate, propellant gas pressure, propellant gas pressure pulse shape, and/or propellant gas flow rate.