Determination of the Temperature in a Solid Propellant Flame by analysis of emission spectra

✍ Scribed by Wilhelm Eckl; Norbert Eisenreich

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 391 KB
• Volume: 17
• Category: Article
• ISSN: 0721-3115
• DOI: 10.1002/prep.19920170411

✦ Synopsis

Abstract

Two methods are described to determine the temperature in a solid propellant flame by analysis of emission spectra. First, experimental spectra of NH and CN radicals were compared with calculated spectra using a least squares fit routine with the parameters temperature T and halfwidth of the line profile Δλ. Second, in flames where no or only small band intensities were observed, the occurring continuous spectra were fitted to a Planck radiation. The emission coefficient ϵ was there by suggested as a function of wavelength λ and temperature T. The first technique was applied to the nitrmine propellant HMX, the second to a composite propellant consisting of 15% AI, 15% GAP and 70% ammonium perchlorate. TO detect the emission, propellant strands were burnt in an optical bomb under nitrogen atmosphere at various pressures (octogen at 0.1 MPa, composite at 2 MPa). To calibrate the intensities of the continous spectra tungsten strip lamp was used. The maximum time resolution of the used spectrometer system is about 10 ms. The determined temperature range was from 2300 K to 3000 K, which is about 20% below the corresponding adiabatic temperature (nitramine propellant: 2900 K, composite propellant: 3500 K).