Spray Morphology and Trajectory of Liquid Jet in Nouniform Subsonic Crossflow

This study employs the high-speed shadowing technique to examine the near-field trajectory and penetration characteristics of water jets in a crossflow with different velocity gradients, which is achieved by different multislot plate version in the same channel located 100 mm upstream of the nozzle. The findings reveal that, under identical average incoming velocities but with a velocity gradient along the jet direction in the crossflow, the jet breakup mode changes due to the variable aerodynamic pressures exerted on the jet and crossflow interface; when the gradient changes from positive to negative, the positive gradient delays the transition of the breakup mode while the negative gradient breaks up earlier, and the spray plume distribution differs, showing three characteristics: elevated oblique throw, oblique throw, and collapse. The penetration height is governed not only by the increment of the momentum flux ratio but is also profoundly influenced by the velocity gradient. Contrasting the uniform flow, the penetration height increases for positive gradients and decreases for negative gradients. Consequently, the empirical formula for the penetration height found based on uniform crossflow is not applicable, and this paper introduces an empirical correlation embracing a novel dimensionless parameter, calibrated for diverse crossflow gradients and generalized operational contexts, aiming to refine atomization characteristics and enhance the atomization model within non-uniform crossflows.