Study On Mechanism Of Novel Volumetric Alternating Cavitation

In the face of the technical problem of precision polishing of the inner surface of tiny cavity,polishing by high-energy shock wave of cavitation collapse has become a new direction of high-energy shock wave polishing.However,cavitation generation methods such as ultrasonic cavitation,hydrodynamic cavitation and laser-induced cavitation have obvious limitations and uncertainties.Therefore,a novel volumetric alternating cavitation method is proposed in this paper to achieve uniform polishing of the inner surface of micro-cavity.The research contents of this paper include:(1)Based on the full analysis of cavitation field and bubble collapse of cavitation water jet,the volume alternating cavitation field is studied,and the mathematical model among frequency,maximum stroke and volume is established based on the operating parameters of volume alternating.(2)The Fluent simulation software was used to simulate the cavitation flow field with different frequency and maximum stroke.The velocity field,pressure field,gas phase volume fraction and morphology evolution of cavitation in the cavity were studied and analyzed,and the influence rule of its working parameters on the cavitation flow field was explored.(3)An experimental system with high speed camera and data acquisition device was set up.At the same time,with the help of Matlab binarization processing technology,the equivalent diameter of the cavity obtained in the experiment was studied,and the cavitation change rule in the micro-cavity was analyzed.(4)The flow field visualization method was used to study the development process of cavitation field and the law of cavitation evolution in micro-cavity.The 3D printed micro-cavity inner surface was taken as the research object to analyze the influence of different operating parameters on the micro-cavity inner surface quality,and to reveal the mechanism of micro-cavity volume alternating cavitation on its surface.