Chris Willert

PLIF Thermometry Based on Measurements of Absolute Concentrations of the OH Radical

Abstract A method for measurements of planar temperature distributions based on planar laser-induced fluorescence (PLIF) of the OH radiacal is described. The technique was developed specifically for the application in lean combustion systems, where OH equilibrium concentrations are largely independent on equivalence ratio and a function of temperature only. It is thus possible to derive a temperature information from measurements of absolute OH concentration, which can be obtained from a combined PLIF/absorption measurement. This paper discusses the basics of the method, and describes validation experiments in high pressure laminar premixed flames which were performed to asses its applicability and accuracy. Therefore, we compared our LIF based results with CARS measurements performed in the same flames. Finally, an example for the application in a lean gas turbine model combustor is discussed.

Phase Resolved Laser Diagnostic Measurements of a Downscaled, Fuel Staged Gas Turbine Combustor at Elevated Pressure and Comparison With LES Predictions

A technical gas turbine combustor has been studied in detail with optical diagnostics for validation of Large-Eddy Simulations (LES). OH* chemiluminescence, OH laser-induced fluorescence (LIF) and particle image velocimetry (PIV) have been applied to stable and pulsating flames up to 8 bar. The combination of all results yielded a good insight into the combustion process with this type of burner and forms a data base which was used for the validation of complex numerical combustion simulations. Large-Eddy Simulations (LES) including radiation, convective cooling and air cooling were combined with a reduced chemical scheme that predicts NOx emissions. Good agreement of the calculated flame position and shape with experimental data was found.Copyright