Study on velocity and pressure characteristics of self-excited oscillating nozzle

Abstract

The mechanism of the self-excited oscillation pulsed jet is still in a period of continuous improvement, and the application breadth and depth of the self-excited oscillation nozzle are significantly limited since the turbulent flow field inside the self-excited oscillation nozzle is exceptionally complex. In this study, computational fluid dynamics numerical simulation and experimental research methods are combined. By changing the structural parameters of self-excited oscillating nozzles, the velocity and pressure characteristics of the self-excited oscillating nozzles were compared and analyzed to determine the important factors that influenced the effect of pulsed jet. These findings demonstrated that the periodic expansion and contraction of the low-pressure vortex ring in the self-excited oscillation nozzle chamber will cause the pressure of the nozzle outlet section to change periodically. The periodic high-voltage blocking and low-pressure speedup of the outlet directly correlate with the pulsed jet. This study shows the reasonable size design range of the self-excited oscillation nozzle, which can guide the design and practical application of the nozzle, as well as provide the theoretical basis for perfecting the self-excited oscillation pulsed jet theory.