Experiments with liquid gun propellants.

Closed chamber and gun firing tests on various liquid monopropellants were performed at the Fraunhofer-Institute (EMI-AFB) and the Ballistic Research Laboratory (BRL). The objectives of the study were twofold: (1) to investigate the ignition requirements of the propellants in both a closed chamber and a gun and (2) to investigate the combustion characteristics of the propellants, also in both a closed chamber and a gun. Pyrotechnis iniggiters were used in both the closed chamber and gun tests. The propellants tested at EMI-AFB were isopropyl nitrate, nitromethane, and three hydroxylammonium nitrate (HAN) based liquid monopropellants, NOS-365, LP 1845 and LP 1846, a variation of LP 1845. The gun tests at EMI-AFB were performed in a 28-mm regenerative liquid propellant gun (RLPG). The propellants tested at the BRL were NOS-365, LP 1845 and LP 1846. The gun tests at the BRL were performed in a 30-mm RLPG. Instrumentation used to evaluate the ignition and combustion properties of the prope llants included pressure and temperature sensors. The temperature measurement is based on an intrusive spectral measurement using a special gage technique.