Determining Electrical Ignition Characteristics of a Gas Propulsion System

Abstract

A technique for determining ignition voltage and minimum ignition energy of a combustible gas propellant in near-actual thruster conditions has been developed. The technique employs electrical state-space response analysis in lieu of more conventional methods such as low-resistance shunting or inductive current monitoring. State-space response analysis circumvents direct measurement of impulsive and inherently noisy ignition sparks. The new technique employs commonly available test equipment and an analysis algorithm readily programmed in an open-source numerical computation environment. It is easily repeatable for evaluating a wide range of ignition conditions such as oxidizer-to-fuel mixture ratio, propellant pressure and temperature, and electrode/chamber geometry. It is currently used for static propellant ignition testing but could be extended to flowing propellant conditions and quenching distance analysis.