UV and Visible Radiation from Magnesium Powder Combustion in Air
Open Access
- Author:
- MacTavish, Teri Marie
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Timothy Miller, Thesis Advisor/Co-Advisor
Timothy Francis Miller, Thesis Advisor/Co-Advisor - Keywords:
- ultraviolet and visible radiation
magnesium
combustion - Abstract:
- Dense cloud powdered magnesium jet deflagration was studied using a linear test combustor. Magnesium is a highly flammable metal that produces copious ultraviolet and visible light emissions during combustion. Understanding of the radiant emission and combustion temperatures is important for application to power and propulsion. Because of the large amounts of broadband UV available and the fact that magnesium emits strongly at germicidal wavelengths indicates a possible anti-bacterial application as well. Two calibration lamps with known values of spectral irradiance and color temperature were used to validate UV and visible wavelength flux measurement and temperature measurement techniques. Silicon photo-diode detectors sensitive to UV were used to determine broadband flux. Collimators, a CCD camera and spectroscope were used to measure spectral emissions in the UV and visible spectrums. Comparison of spectral emissions was compared to Planck’s law predictions using an automated algorithm to permit inference of combustion temperatures. Comparison with the temperature standard indicated an error of ~ 60 K at 3000 K temperature. Spectral extinction coefficients in a bacteria suspension were also measured as a function of concentration. These procedures were applied to measurements in a linear magnesium powder and air combustor. The flame temperature of magnesium combustion was determined to range from 2500-3500 K, depending on the location and air/fuel ratio. The predicted temperatures are comparable to previously published data and to values found from adiabatic flame temperature predictions using a chemical equilibrium computer code. The broadband UV fluxes emitted at different locations were also measured.