The Numerical Simulation of Collapse Pressure and Boundary of the Cavity Cloud in Venturi

• Published in: Chinese journal of chemical engineering Vol. 17; no. 6; pp. 896 - 903
• Main Author: 张晓冬 付勇 李志义 赵宗昌
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2009
• Subjects: bubble dynamics; cavity cloud; collapse pressure; collapsing layer by layer; hydrodynamic cavitation; 仿真结果; 外边界; 开发理念; 数值模拟; 流体可压缩性; 界面张力; 超声空化; collapse pressure; cavity cloud; hydrodynamic cavitation; collapsing layer by layer; bubble dynamics
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60294-3

The idea that the collapse proceeds from the outer boundary of the cavity cloud towards its center for the ultrasonic cavitation proposed by Hasson and Morch in 1980s is further developed for calculating the collapse pressure and boundaries of cavity cloud at the collapse stage of bubbles for hydraulic cavitation flow in Venturi in present research. The numerical simulation is carried out based on Gilmore＇s eouations of bubble dynamics, which take account of the compressibility of fluid besides the viscosity and interfacial tension. The collapse of the cavity cloud is considered to proceed layer by layer from the outer cloud towards its inner part. The simulation results indicate that thepredicted boundaries of the cavity cloudat the collapse stage agree.well with the exPerimental ones.It is also found that the maximum collapse pressure of the cavity cloud is several times as high as the collapse pressure of outside boundary, and it is located at a point in the axis, where the cavity cloud disappears completely. This means that a cavity cloud has higher collapse pressure or strength than that of a single bubble due to the interactions of the bubbles. The effects of operation and structural parameters on the collapse pressure are also analyzed in detail.