Regenerative Electrical Igniter for a Liquid Propellant Gun

摘要

A novel igniter for a regenerative liquid propellant gun (RLPG) is described, which utilizes only the liquid gun propellant (LGP). The liquid which is sealed in the igniter is ignited by an arc discharge causing a rise in pressure. At a predetermined pressure the igniter opens and gas products and unreacted liquid are injected to mix and react externally. The liquid jet derives it injection pressure hydraulically from the constantly generated internal gas pressure. The igniter is self-regulating to operate below a certain internal pressure. Two exploratory configurations of the injector were used, both containing 4.5 cc of LGP 1845 or LGP 1846. The injectors were fired into open air as well as into a 500 cc windowed closed chamber (simulating a gun chamber). Their discharge was photographed and the pressure rise in the chamber was measured. The LGP was electrically ignited using less than 50 J, and with as little as 300 V on the electrodes. Three electrode configurations were tested. Successful operations of the injectors were achieved with opening pressures above 18 MPA resulting in complete injection of the LGP and products in less than 6 msec. In tests when the LGP burnt to completion, the pressure rise in the combustion chamber was rather steep, ranging from tens to hundreds of MPa per msec. Although the igniters need much refinement to reach true practicality, they are nevertheless deemed highly promising.