title: Experimental and theoretical analysis of secondary Bjerknes forces between two bubbles in a standing wave.
abstract: Bubbles in an acoustic field are affected by forces such as primary and secondary Bjerknes forces, which have been shown to be influenced by acoustic pressure, frequency, bubble size and separation distance between bubbles. However, such studies are predominantly theoretical, and are mostly focused on the sign reversal of the secondary Bjerknes force. This study provides experimental data on the effect of a range of bubble sizes (8-30 μm), distances (⩽0.2 mm), acoustic pressures (20-40 kPa) and frequencies (40-100 kHz) on the relative acceleration of two approaching bubbles. Under these conditions, only variations in the magnitude of the attractive force were observed. Using coupled equations of radial and translational motions, the acceleration and secondary Bjerknes force were calculated and compared to the experimental data. The variations in the magnitude of the secondary Bjerknes forces were explained by simulating bubble radius and coupled volume oscillation as a function of time.
authors.affiliation: Department of Mechanical Engineering, Nanjing University of Science and Technology, Jiangsu, China; Particulate Fluids Processing Centre, School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia.
authors.forename: Junjie
authors.initials: J
authors.lastname: Jiao
authors.affiliation: Department of Mechanical Engineering, Nanjing University of Science and Technology, Jiangsu, China. Electronic address: yhe1964@mail.njust.edu.cn.
authors.forename: Yong
authors.initials: Y
authors.lastname: He
authors.affiliation: Particulate Fluids Processing Centre, Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Kentish
authors.affiliation: Particulate Fluids Processing Centre, School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia; Adjunct Professor, Chemistry Department, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Muthupandian
authors.initials: M
authors.lastname: Ashokkumar
authors.affiliation: Mechanical and Product Design Engineering, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
authors.forename: Richard
authors.initials: R
authors.lastname: Manasseh
authors.affiliation: Particulate Fluids Processing Centre, Chemical and Biomolecular Engineering, University of Melbourne, Parkville, VIC 3010, Australia. Electronic address: jytlee@unimelb.edu.au.
authors.forename: Judy
authors.initials: J
authors.lastname: Lee
keywords: Acceleration; Bubble size; Frequency; Pressure; Secondary Bjerknes force