Affiliations: School of Mechanical Engineering and Automation,
University of Science and Technology Liaoning, Anshan, Liaoning, China | Department of Material Science and Engineering,
Saitama Institute of Technology, Fukaya, Saitama, Japan
Note: [] Corresponding author: Bing Han, School of Mechanical Engineering
and Automation, University of Science and Technology Liaoning, No. 185,
Qianshan Midroad, Hi-Tech Zone, Anshan 114051, Liaoning, China. Tel.: +86 412
592 8271; Fax: +86 412 592 8271; E-mail: hanb75@126.com
Abstract: Water-jet cavitation peening (WCP) is a new technology for the
surface modification of metallic materials. The cavitation behavior in this
process involves complex and changeable physics phenomena, such as high speed,
high pressure, multiple phases, phase transition, turbulence, and unstable
features. Thus, the cavitation behavior and impact-pressure distribution in WCP
have always been key problems in this field. Numerous factors affect the
occurrence of cavitation. These factors include flow-boundary conditions,
absolute pressure, flow velocity, flow viscosity, surface tension, and so on.
Among these factors, pressure and vapor fraction are the most significant.
Numerical simulations are performed to determine the flow-field characteristics
of both inside and outside the cavitating nozzle of a submerged water jet. The
factors that influence the cavitation intensity of pressure are simulated.
Fujifilm pressure-sensitive paper is used to measure the distribution of impact
pressure along the jet direction during the WCP process. The results show that
submerged cavitation jets can induce cavitation both inside and outside a
conical nozzle and a convergent-divergent nozzle when the inlet pressure is
32 MPa. Moreover, the shock wave pressure induced by the collapse of the bubble
group reaches up to 300 MPa.
