Experimental Investigations of an Axially Staged Combustor Sector with Optical Diagnostics at Realistic Operating Conditions

Abstract

A rectangular sector of an axially staged combustor built by BMW-RR was investigated with optical diagnostics in a newly built experimental facility at DLR Cologne. The goal of the investigation was to acquire data on the combusting flow field of a practical combustor at realistic operating conditions to aid the design and validate results achieved with computational fluid dynamics (CFD). The rig is capable of operating at pressures up to 20 bar, preheat temperatures of 850K and air mass flows of 10 kg/s. The combustor is optically accessible through the side windows and the combustor liners, which allows the use of planar imaging techniques. The measurement techniques applied so far are Doppler Global Velocimetry (DGV) for the isothermal flow, Laser Doppler Anemometry (LDA) for the gas velocity of the combusting flow, Phase Doppler Anemometry (PDA) for size and velocity of fuel droplets and Mie scattering of Kerosene for the imaging of the liquid fuel concentration. The reaction zone was investigated with measurements of the spontaneous OH emission. The paper reports results and experiences from those measurements at 1 and 6 bar. Application of CARS and OH-LIF for the in situ measurement of temperature and the extension of the application to 20 bar are planned for the immediate future.