Working Characteristics of a New Self-Excited Sweeping Nozzle

In view of the urgent need for improving fuel atomization performance and oil-gas mixing uniformity of aero-aircraft engines and other aerospace power units，a new self-excited sweeping nozzle with spoiler column structure is proposed，which can realize self-excited sweeping oscillation liquid fuel injection at 0.5mm diameter scale. Using a variety of experimental methods such as high-speed shadowgraph imaging and laser particle size measurement，with water and aviation kerosene at the characteristic scale of 0.5mm，the response of mass flowrate，working frequency，sweeping angle and atomized particle size of the new self-excited sweeping nozzle to the working pressure drop was studied. The results show that the new self-excited sweeping nozzle can achieve stable self-excited sweeping oscillation in a wide working pressure range（0.05~5MPa），resulting in a sweeping opening angle of more than 50° and an oscillation frequency of more than 1600Hz，and its sweeping angle and the Strouhal number characterizing the working frequency remain constant in a wide working pressure range. Compared with the plain-orifice nozzle，the flowrate coefficient increases by 12%，and the atomization capacity is improved by orders of magnitude. This study preliminarily verifies the application feasibility of the new self-excited sweeping nozzle under the typical application environment and working conditions of aerospace power units. © 2023 Journal of Propulsion Technology. All rights reserved.