Investigation of high pressure solid propellant combustion chemistryusing emission spectroscopy

Abstract

A survey of the chemiluminescent emission in the range from 280 and 800 nm from the flames of ammonium perchlorate (AP)and HMX-based solid propellants has been performed at pressures from atmospheric to 7 MPa (1000 psig). The AP propellant flame showed the emission of CH, CN, NH, and OH at atmospheric pressure (under nitrogen), as well as emission from several trace impurities such as Na, K, and Ca. As the pressure was increased, the banded molecular emission of all molecules except OH was rapidly obscured by a continuum that spanned the range 350-550 nm. In contrast, the HMX propellant showed CN, NH, and OH emission at pressures up to 7 MPa. CH emission was not detected in the HMX flame at any pressure; C2 emission was not detected in either propellant flame. Spatial intensity distributions of emitting species were obtained, showing OH and atomic emission spatially distributed throughout the propellant flame and CN and NH emission confined to the region near the surface.