Investigation of influence of geometry of jet orifice of throttling device on formation of cavitation

Abstract

Throttling devices are used in hydraulic systems both as regulating valves and to provide protective functions, which determines the relevance of developing such a design that will ensure their cavitation-free operation. The aim of the study is to investigate cavitation phenomena in single-stage throttling devices with different geometry of the jet orifices in order to identify the geometric shape capable of minimizing cavitation. The paper presents a study of the effect of different geometric shapes of the orifices of single-stage throttling devices on cavitation formation in the low-pressure areas. In addition, the objective of the study is to investigate the influence of physical quantities (velocity and pressure) on cavitation formation and to carry out a comparative analysis by means of which the influence of the correlation between the geometrical shape of the orifice of the jets, the velocity of the working medium and the pressure in the area of the orifice of the jets on the formation of cavitation zones in the areas of reduced pressure is clearly demonstrated. The computational experiment was conducted using Ansys CFX software and was based on the Rayleigh-Plesset mathematical model of cavitation. The study investigated the possibility of cavitation phenomena in single-stage throttling devices, and identified the geometric shape of the jet orifice that promotes cavitation-free operation of the single-stage throttling device. Thus, the results of the study show that the jet with a conical orifice minimizes the volume fraction of vapor, arising during cavitation processes, in single-stage throttling devices. The conducted research has practical significance and can increase the service life of single-stage throttling devices by minimizing the formation of cavitation zones in areas of low pressure.