Drop-size distribution for crosscurrent breakup of a liquid jet in a convective airstream

Abstract

Experimental investigations have been completed in the study of a simulated fuel injector system implementing an airblast atomization process called a jet in a crossflow as the primary means of fuel atomization. To complete these studies an apparatus has been designed and constructed. A laser diffraction particle analyzer technique is used to spatially measure the spray Sauter-Mean Diameters. The Rosin-Rammler two parameter model is assumed for the droplet size distribution. Injection pressure for the injected liquid, distilled water, is held constant at 10.240 atm for the five different nozzle orifice diameters. A water rotameter is used to vary flowrates from 0.75 to 5.0 GPH and airflow Reynolds numbers are set at 50,000, 60,000, and 70,000 depending on the desired condition. SMD shows an increase in size for an increased distance from the top to the bottom of the test channel which is defined as the Y-Position from the orifice exit. The SMD growth rate decreases for increased water flowrates for a given airflow and orifice injector. For equal air-to-liquid ratios, overall SMD increases as the water flowrate and airflow Reynolds number combinations decrease. Overall SMD decreases for decreased air-to-liquid ratios. SMD decreases as the spray progresses downstream of the orifice exit in the direction of the airflow (X-Position) for a constant Y-Coordinate. A correlation of SMD-to-orifice diameter is determined to be as follows: [ ]