Interpretation of optical emissions for sensors in liquid fueled combustors

The optical emissions from a turbulent, nonpre-mixed, liquid fueled (n-heptane) combustor were investigated using two optical imaging systems: a high spectral resolution (~0.3 nm), single wavelength system; and a low resolution (~5 nm), multi-wavelength system intended to mimic the response of a practical sensor. The goal was to develop signal interpretation strategies that would allow an optical sensor system to monitor needed properties in liquid-fueled combustors and engines. The research focused on the chemilumi-nescent emissions from OH*, CH*, and C2*. Data were acquired for a range of fuel and air flow rates (equiva-lence ratios 0.6-1.3), and for radial slices through the nominally axisymmetric combustor over the complete