Two-Stage Igniter Test Results: Electrical Ignition of LGP 1846

摘要

Test results from a two-stage, electrical liquid propellant igniter aredescribed. Two critical areas are identified relating to the operation of the igniter. The first is the confinement of the liquid propellant in the ignition cavity and the second is the interaction of the gases venting from the precombustion chamber with the liquid propellant booster charge in the antechamber. The design modifications made to ensure proper operation are presented. Typical electrode gap voltage and current values ranged from approximately 1,000-1,500 V and approximately 175-185 A, respectively. The energy dissipated into the igniter ranged from 21-30 J, with only 10-30% of this energy due to the arc phase of the discharge. Typical maximum pressures were 502 MPa in the precombustion chamber and 329 MPa in the antechamber. The results of five tests staging up to the maximum booster charge are also presented. The average test chamber pressure rise time in these five tests was 3.55 ms, or about 5.4 MPa/ms in the test at maximum charge. A test successfully demonstrating arcless ignition is also presented. The performance with arcless ignition was comparable to that achieved in arc-based ignition tests.