Xiaojun Zhang, Luqiao Yao, Qin Zhu, Liping Wang, and Songlin Nie. Numerical investigation of the pulsed oscillation flow in the self-sustained cavitating jet nozzle. Dynamic Systems and Applications 29 (2020) No. 7, 2488 – 2504

https://doi.org/10.46719/dsa20202979

ABSTRACT.
In recent years, the high-pressure water jet has been applied to more and more fields. The pulsed jet is often adopted to improve the hydraulic horse power upon the work pieces and the effect of crash and cleaning. This paper discusses the phenomena of flow oscillation coupling when an unstable turbulence shear layer across the cavity, thereby forming the self-sustained oscillation pulsed jet. This paper introduces a novel self-sustained oscillation pulsed jet nozzle and also optimize structure that the usage of such nozzle for fire-fighting engineering. These cavity oscillations have been studied steadily for half century, however, by now the detailed transient flow field, the originating mechanism and the potential application of unsteady flow are unclear or not enough understood. Therefore, this dissertation, making use of the numerical simulation, is aimed towards providing a revelation of the characteristics of the jet flow, and the influence on the jet for different structure factors of cavity also will be investigated deeply. A lot of contour maps of flow field show that the self-excited pulsed jet nozzle can make jet generate higher amplitude of pressure, and it could make jet increase the effective range. The validation underlined the applicability and efficiency of the theory model, which made it useful for engineering applications.

Keyword: self-sustained, oscillation, pulsed jet, computational fluid dynamics.