Experimental study on the change of the orientation of high aspect ratio nozzle slit relative to the airflow.

An experimental study to investigate the flow of liquid jet issued from a high aspect ratio nozzle slit into an incoming airflow by changing the orientation angle from the incoming free-stream was performed. A two-dimensional liquid sheet emerged from the narrow slit into the subsonic air crossflow. Different orientation angles between 0 and 90 degrees were studied. High-speed photography and shadowgraphy techniques were utilized to visualize the flow physics. The influence of the slit orientation angle on the flow morphology and the flow regimes of liquid sheets was investigated. Some fluid flow parameters were obtained by analyzing the images. The changes in breakup height of different orientations were measured. A model was offered for the breakup height of the liquid sheet based on the liquid-to-gas momentum ratio, gas Weber number, and a new non-dimensional parameter as a representation of the angle of slit orientation. Also, the defined sheet trajectory for each orientation angle was obtained, and the variations were examined. Empirical correlations for the defined trajectory of the sheet in terms of liquid to gas momentum ratio and gas Weber number for each orientation angle were proposed.