Experimental and Theoretical Investigation of a Research Atomizer/Combustion Chamber Configuration

Abstract

A research airblast atomizer/combustion chamber configuration has been built for the validation of a mathematical model of two phase flows in gas turbine combustors. The inlet boundary conditions of the gas flow were measured within the nozzle by Laser-Two-Focus-Velocimetry. Starting velocities and mass fluxes for the droplet sizes of the spray were measured by Phase-Doppler-Anemometry at a plane 7mm downstream of the atomizer lip. Gas- and drop velocities were measured consecutively in the confined swirling isothermal flow throughout the combustor and were compared with the results of a newly developed mathematical model of spray dispersion. The spray shows the general structure of an axial acceleration of all dropsizes and a following dispersion of the droplets and radial separation by centrifugal forces according to their size. Measured and calculated drop velocities for 10, 30 and 50μm drops compare well, except for some differences, which can be explained by deficiencies of the gas flow calculation. Mass flux and volumetric mean diameter profiles are also correctly reproduced.