Lab-scale ballistic and safety property investigations of LMP-103S

Abstract

LMP-103S is a storable, green, ammonium dinitramide (ADN)-based liquid monopropellant with significant potential owing to its improved specific impulse (≥ 6%) and density (∼24%) in comparison to hydrazine, and its superior safety and handling characteristics. LMP-103S already has a significant history of thruster testing and flight heritage. However, its baseline combustion behavior is a surprisingly understudied topic. Constant-volume strand burner experiments with LMP-103S are reported herein for pressures between 0.69 and 34.5 MPa (100 – 5,000 psia). Linear burning rates were measured from transient pressure data and high-speed video. Visible and near-IR emission spectra were recorded as well. Phenomenological combustion behaviors are reported for the entire pressure range as deduced from these diagnostics, and two clear pressure regimes are observed. Hydrodynamic instabilities and supercritical combustion processes dominate the combustion behavior in the low- and high-pressure regimes, respectively. Supporting experiments include thermal cook-off of LMP-103S and impact sensitivity testing of ADN crystals extracted from LMP-103S solution. The data presented herein significantly expand upon those available in the literature for LMP-103S, and the phenomenological combustion behavior deduced from transient, high-speed video data improve upon the state-of-the-art knowledge regarding ADN-based liquid monopropellants.