Abstract

A major new research facility consisting of a low-pressure burner apparatus has been constructed at the Ballistic Research Laboratory to study the detailed flame chemistry relevant to the gaseous flames of burning propellants. Experimental results provide temperature and species profiles that are necessary to validate flame models being developed to simulate propellant combustion. This facility is an integrated apparatus that consists of various diagnostic tools which include laser spectroscopy, Fourier transform infrared spectroscopy, and molecular beam triple quadrupole mass spectrometry. In this paper, we report on spatially resolved temperature and species profiles obtained in premixed H₂/N₂O/Ar and H₂/NO₂/Ar low-pressure flames (20 Torr). The temperature measurements were obtained by laser-induced fluorescence (LIF) of OH radical employing its (A²Σ⁺–X²Π) (1,0) band near 281 nm. Temperatures were abstracted from a Boltzmann energy simulation and compared with those obtained with Pt/Pt-Rh(10%) thermocouples coated with noncatalytic beryllium/yttrium oxide. Species profiles include H, H₂, O, OH, N₂O, NO, NO₂, O₂, H₂O and NO₂. Profiles for radical species such as OH and NO are compared with those obtained with LIF and/or resonant-enhanced multiphoton ionization to ensure that there are no systematic errors in a given technique.

© 1991 Optical Society of America