Date of Award
Doctor of Philosophy (PhD)
Department of Engineering Physics
Glen P. Perram, PhD.
A midwave infrared (MWIR) imaging Fourier transform spectrometer (IFTS) was used to successfully capture and analyze hyperspectral imagery of combustion plumes. Jet engine exhaust data from a small turbojet engine burning diesel fuel at a flow rate of 300 cm3/min was collected at 1 cm−1 resolution from a side-plume vantage point on a 200x64 pixel window at a range of 11.2 meters. Spectral features of water, CO, and CO2 were present, and showed spatial variability within the plume structure. An array of thermocouple probes was positioned within the plume to aid in temperature analysis. A single-temperature plume model was implemented to obtain spatiallyvarying temperatures and plume concentrations. Model-fitted temperatures of 811 ± 1.5 K and 543 ± 1.6 K were obtained from plume regions in close proximity to thermocouple probes measuring temperatures of 719 K and 522 K, respectively. Industrial smokestack plume data from a coal-burning stack collected at 0.25 cm−1 resolution at a range of 600 meters featured strong emission from NO, CO, CO2, SO2, and HCl in the spectral region 1800-3000 cm−1. A simplified radiative transfer model was employed to derive temperature and concentrations for clustered regions of the 128x64 pixel scene, with corresponding statistical error bounds. The hottest region (closest to stack centerline) was 401 ± 0.36 K, compared to an in-stack measurement of 406 K, and model-derived concentration values of NO, CO2, and SO2 were 140 ± 1 ppmV, 110,400 ± 950 ppmV, and 382 ± 4 ppmV compared to in-stack measurements of 120 ppmV (NOχ), 94,000 ppmV, and 382 ppmV, respectively. In-stack measurements of CO and HCl were not provided by the stack operator, but model-derived values of 19 ± 0.2 ppmV and 111 ± 1 ppmV are reported near stack centerline. A deployment to Dugway Proving Grounds, UT to collect hyperspectral imagery of chemical and biological threat agent simulants resulted in weak spectral signatures from several species. Plume detection of methyl salicilate was achieved from both a stack release and explosive detonation, although spectral identification was not accomplished due to weak signal strength.
DTIC Accession Number
Bradley, Kenneth C., "Midwave Infrared Imaging Fourier Transform Spectrometry of Combustion Plumes" (2009). Theses and Dissertations. 2156.