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This study aims at the array ultrasonic nozzle sprayed atomization flow field on flat plate, and uses different design and operating parameter combinations to analyze the distribution of spray flow field, the analytic results can be used to improve the flat plate coating performance of the array ultrasonic nozzle spraying equipment. The simulation analysis results will be compared and validated by practical spray coating experiment, so as to determine the reliability of simulation to implement the spray flow field simulation technique for large area uniform spray coating. The mean error value is less than 24%, proving that the simulation results have certain feasibility and accuracy.

The main function of a fuel injector nozzle is to break fuels into droplets, form the spray pattern, and propel the droplets into a combustion chamber. The amount of spray volume at a given operating pressure, the travel speed, and spacing between the jets of fuel can also be determined by the nozzle. In fuel injection, the smallest possible droplet size is desired for the most flow. This work presents an opportunity to use the Schlieren arrangement as a visualization method to view the flow of fuel from a three-hole fuel injector nozzle which cannot be seen by the naked eye. The jet flow of diesel Fuel was investigated by Schlieren photography. A test rig was designed and constructed to accommodate the nozzle; optical mirrors were arranged according to Schlieren specifications in order to allow the jet to be photographed. The breakaway pressure of the nozzle was varied between 60bar to 80bar. Each hole of the nozzle is 0.26mm in diameter and 120° apart; the third jet could not be seen from the images because the camera took x-y dimension images. The spray pattern observed from the two dimensional images of the jets developed were seen to be well dispersed. Su et al [3] found that emissions could be reduced in diesel engines if the injector nozzle produces smaller and more dispersed droplets.

This study aimed to make the slurry droplets atomized by the ultrasonic atomization spray coating diversion system fall on the substrate surface of hot plate stably, instead of rebound or spill due to overly high pressure or speed that causes material waste and excessive or non-uniform spray coating. The lateral movement distance of the nozzle influences the uniformity of film thickness distribution, while the lateral movement distance influences the film uniformity and the spray coating efficiency; these two are important parameters to the efficiency of ultrasonic spraying equipments. Therefore, this study conducted a simulation analysis on the atomization flow field of ultrasonic atomization diversion systems, where the distribution of atomization flow field was analyzed at different lateral movement distances of the nozzle. By evaluating the performance of thin film coating, this study attempted to find out the optimal lateral movement distance of ultrasonic precision spray coating. The simulation analysis results were tested on a real machine for validation in order to identify the reliability of the simulation. The simulation result showed that the central part of the film in the position sprayed was thicker; therefore, the nozzle moved 1 cm horizontally at 0.1m/s to thicken the repeatedly sprayed area to improve the overall uniformity of the panel. The study analyzed the spray coating thicknesses according to 16 monitoring points in the repeatedly sprayed area on the panel. According to the thicknesses of the monitoring point positions, when the area that had been sprayed once was sprayed again by the nozzle moving 1cm laterally, the uniformity of overall film on the overall panel was improved significantly.