Novel Laser-Based Diagnostics for Quantitative Characterization of Burning in the Turbine Phenomenon
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5100 Springfield Street, Suite 301, Dayton, OH, -
AbstractABSTRACT: There are two overarching objectives of the Phase-I research effort. The first objective would be to provide non-invasive optical measurements for quantifying the pattern factor of the exhaust products from a Well-Stirred Reactor when it is entering a test-section that includes turbine blades with various cooling-hole configurations. The second overarching objective would be to present data from the areas near the turbine blades, including temperature, OH concentration, local heat release, and local equivalence ratio profiles for various cooling-hole configurations and blowing ratios between the combustor exhaust and coolants. The measurements will be geared toward addressing the following issues: (1) Quantify the conditions that result in"burning in the turbine;"(2) Quantitatively determine the effects of various cooling-hole configurations in preventing or reducing the heat release related to this secondary combustion near the turbine blade; (3) Identify the areas that need to be cooled based on a 2D measurement of heat-release rates near the turbine blade; (4) Identify coolant-delivery methods to the needed areas guided by quantitative measurements of temperature and species concentrations; and (5) Validate that coolant maintains vane at acceptable temperatures without burning. The specific task objectives are to obtain three measurements: The first is a measurement of the 2D temperature profiles of the exhaust products coming out of a well-stirred reactor connected to the turbine-blade test section using two-color OH PLIF. The second is a measurement of 2D temperature and OH-concentration profiles near the turbine blades for various flow conditions, shedding light onto the reactions near the turbine. OH PLIF images will also help to mark the reaction zones near the turbine blades. The third specific objective is to measure 2D heat release and equivalence ratio profiles near the turbine blades, utilizing an innovative hyper-spectral emission. This innovative sensor system will provide spectrally-resolved, two dimensional images of OH*, CH*, C2*, and CO2*at a speed of 20 kHz, thereby allowing for the calculation of local heat release and equivalence ratios from the ratios of OH*/CH* and C2*/OH*, respectively. BENEFIT: The proposed research effort will provide new diagnostic capabilities that will enable the Air Force and gas-turbine-system manufacturers to address the challenges associated with the development of compact combustors and their integration with turbines. These tools are critical for the development and long-term health of propulsion systems for high-performance military as well as for commercial systems. The proposed research will also help to advance the state-of-the-art turbine-cooling technology by quantitatively identifying various factors that lead to burning in the turbine and then by designing innovative cooling configurations for preventing burning near the turbine blades. Quantitative measurements are critical for validating numerical models of reacting and non-equilibrium phenomena affecting modern gas-turbine and hypersonic propulsion systems. The data-analysis tools will be very valuable for reduction of data and identification of various instability modes in turbulent reacting flows; it should be applicable to any measurement techniques involving high data bandwidth. Such experimental and numerical tools will enable analysis of military and commercial gas-turbine combustors, as well as of applications with limited optical access such as internal combustion engines and stationary power-generation systems.
* information listed above is at the time of submission.