Experimental Techniques for the Study of Liquid Monopropellant Combustion

Abstract

Propellants based on hydroxylammonium nitrate (HAN) have shown promise as a hydrazine replacement because of their comparably low toxicity, low vapor pressure, high specific impulse and high density. Herein, the recent history of advanced monopropellant research is explored, and new experimental techniques are presented to investigate the combustion behavior of a potential hydrazine replacement propellant. Nitromethane, a widely available monopropellant with a recent resurgence in research, is utilized in the current study as a proof of concept for the newly designed equipment and as a step towards investigating more-advanced, HAN-based monopropellants.

A strand bomb facility capable of supporting testing at up to 340 atm was employed, and experiments were performed between 28 atm and 130 atm. Burning rate data for nitromethane are calculated from experiments and a power correlation is established as r(mm/s) = 0.33[P(MPa)]^1.02.

A comparison with available literature reveals this correlation to be very much in agreement to other studies of nitromethane. Other physical characteristics of nitromethane combustion are presented. Updates to the facility and new methods to examine the combustion of liquid propellant are described in detail. Special focus is given to procedures and safety information.