Study of an Airblast Atomizer Spray in a Lean Burn Aero-Engine Model Combustor at Engine Conditions

Abstract

This contribution reports on results of fuel spray caracterization experiments in the primary zone of a lean combustor equipped with a piloted injector with airblast atomization. Tests were performed at idle and engine cruise conditions in an optically accessible high pressure single sector rig, using planar Mie scattering and Phase Doppler Anemometry (PDA). In the case of PDA; the primary goal was to perform a survey to explore the applicability of PDA in combusting high pressure two phase flows, and to develop strategies for optimization and validation of the technique under such conditions. Data on liquid fuel placement, droplet velocities and sizes are presented and discussed. Size-dependent droplet velocities and Sauter mean diameters were measured at different axial and radial positions in the combustor, showing generally small droplets. Velocities of droplets with different sizes were found to be generally similar. The data illustrate the necessity of a careful design of the optical arrangement and operation parameters of a PDA setup under the adverse conditions existing in a jet engine combustor.