WAVELENGTH-AGILE ABSORPTION SPECTROSCOPY FOR MEASURING TEMPERATURE AND H2O MOLE FRACTION IN HARSH ENVIRONMENTS
Date
2009-06-24Author
Kranendonk, Laura A.
Advisor(s)
Sanders, Scott T.
Metadata
Show full item recordAbstract
This project develops the necessary tools and methods to measure H2O absorption spectra
in harsh environments, and calculate temperature and mole fraction from the measured spectra.
Various wavelength-agile sources are designed to obtain absorption spectra. The best
performing wavelength-agile laser source for H2O measurements to date is the Fourier-Domain
Mode-Locking laser. Specific procedures are highlighted to best accommodate the
measurements in the presence of beam steering and thermal emission. A robust method to
calculate temperature and absorber mole fraction is also developed.
Measurements were taken to quantify accuracy in a shock tube and steady burner (used to
stimulate gas turbine conditions). Results from HCCI engine measurements demonstrated the
precision of the measurements. Temperature results greater than 1000 K have been shown to be
biased low. This is a major concern since the main function of the sensor is high temperature
combustion studies. Preliminary studies indicate that using a better database for reference
spectra should improve these high temperature results.