High-Speed, Multispecies Sensing in Gas Turbine Engines and Augmentors

ABSTRACT: Measurements of combustion and gas dynamic properties inside gas turbine engines and augmentors are needed to aid in engine development, performance testing and evaluation, and for verification and validation of combustion modeling codes. Flame emission spectra in the ultraviolet and visible portions of the spectrum can be used to determine species concentrations, fuel-air ratio, and instantaneous heat release in liquid fueled gas turbine combustors. In Phase I, Bodkin Design & Engineering demonstrated snapshot hyperspectral imaging of hydrocarbon flames simultaneously recording spatial and spectral data. In Phase II, we will design a custom multi-modal sensor system that will measure multiple species concentrations (including free radical species such as OH*, CH* and C2*), local fuel/air ratios, heat release, and fuel/air mix temperature inside a gas turbine engine or augmentor. The system will use fast, compact spectral imagers operating simultaneously at both ultraviolet (UV/vis) and short-wave infrared (SWIR) wavelengths and will record hyperspectral images at frame rates as high as 2000 Hz. The completed system will be demonstrated on the J85 engine test stand at UTSI. BENEFIT: Combustion diagnostics has been an important area of research for half a century. Key improvements have led to more fuel efficient and less polluting engines of all types including aircraft and automotive engines, industrial furnaces, and power generating turbines. The system to be developed in this project will directly benefit the Air Force in its development of better jet engines since it will be an important tool for imaging fast, dynamic instabilities in combustion zones while simultaneously providing important chemometric and thermometric data.