INFLUENCE OF AN OSCILLATING AIRFLOW ON THE PREFILMING AIRBLAST ATOMIZATION PROCESS

Thermoacoustic instabilities often occur in a combustion chamber of jet engine when pressure fluctuations from the released heat create closed feedback loop with inlet air velocity, causing further that enhance cycle back again. Since most chambers use liquid fuel dispersed into droplets by an airblast atomizer, any occurring entering nozzle could affect atomization process and air-to-fuel ratio distribution inside combustor. The present experimental study focuses on influence pulsating airflow spray characteristics during process. experiments were carried out two-dimensional prefilmer which water film flow was generated one surface. A siren excited at approximately 120 Hz. oscillation characterized constant temperature anemometer, while developed examined using phase doppler anemometry where droplet velocities size measured. By processing characteristics, mean diameter, Sauter diameter (SMD), velocity is observed. In comparison to nonforced case as well theoretical predictions SMD based these results may indicate oscillating causes time-dependent separation droplets, those fluctuating characteristics.