EFFECT OF NOZZLE GEOMETRY ON BREAKUP LENGTH AND TRAJECTORY OF LIQUID JET IN SUBSONIC CROSSFLOW

The effect of a nozzle's internal geometry on a water jet issuing into a subsonic cross air flow was studied experimentally to determine the jet's breakup length and trajectory. The geometrical parameters considered were the nozzle's diameter, nominal surface roughness, length-to-diameter ratio and contraction angle. Although the nozzles employed were not transparent, near-field photographs and column breakup lengths of a water jet discharged into a quiescent atmosphere (i.e., having no airflow) allowed conditions to be identified that promoted cavitation or hydraulic flip. Results revealed that a nozzle's geometry influenced the corresponding water jet's breakup length only at high momentum flux ratios. Furthermore, the trajectory of a water jet from a nozzle experiencing cavitation or hydraulic flip, when discharged into a subsonic crossflow, was found to be almost insensitive to the nozzle's geometry.