FUEL ATOMIZATION ANALYSIS FOR ADVANCED GAS TURBINE COMBUSTORS

CURRENT STATE-OF-THE-ART CFD SPRAY COMBUSTION CODES DO NOT MODEL THE ATOMIZATION PROCESS, AND USE EMPIRICALLY/ARBITRARILY PRESCRIBED DROPLET CHARACTERISTICS AT THE FUEL INJECTOR EXIT. THIS CRITICAL SHORTCOMING IMPEDS THE ANALYSIS OF IMPORTANT ASPECTS OF GAS TURBINE COMBUSTION. IN PHASE I OF THIS PROJECT, A COMPUTATIONAL MODEL OF THE ATOMIZATION PROCESS WILL BE DEVELOPED FROM FUNDAMENTAL PRINCIPLES,USING FILM DYNAMICS AND SURFACE WAVE INSTABILITY FORMULATIONS. THE COMPLETE PRIMARY BREAKUP PROCESS WILL BE MODELED, INCLUDING FILM STRETCHING, FORMATION OF CIRCUMFERENTIAL RIBBONS AND LIGAMENTS, AND DISTINGRATION OF LIGAMENTS INTO DROPLETS. SUCH AN INNOVATIVE APPROACH WILL ALLOW THE ACCURATE PREDICTION OF DROP SIZE AND DROP VELOCITY DISTRIBUTIONS FROM AIRBLAST AND PRESSURE FUEL INJECTORS. IN PHASE II, THE ATOMIZATION MODEL WILL BE ENHANCED TO INCLUDE SECONDARY ATOMIZATION, VAPORIZATION AND COMBUSTION, AND THEN COUPLED TO AN EXISTING CFD EULERIAN-LAGRANGIAN SPRAY COMBUSTION CODE. EXTENSIVE VERIFICATION AND VALIDATION STUDIES WILL BE PERFORMED, CULMINATING IN THE COMPARISON OF LEAN BLOWOUT WITH EXPERIMENTAL MEASUREMENTS.