title: An experimental study on the coalescence process of binary droplets in oil under ultrasonic standing waves.
abstract: The coalescence process of binary droplets in oil under ultrasonic standing waves was investigated with high-speed photography. Three motion models of binary droplets in coalescence process were illustrated: (1) slight translational oscillation; (2) sinusoidal translational oscillation; (3) migration along with acoustic streaming. To reveal the droplets coalescence mechanisms, the influence of main factors (such as acoustic intensity, droplet size, viscosity and interfacial tension, etc) on the motion and coalescence of binary droplets was studied under ultrasonic standing waves. Results indicate that the shortest coalescence time is achieved when binary droplets show sinusoidal translational oscillation. The corresponding acoustic intensity in this case is the optimum acoustic intensity. Under the optimum acoustic intensity, drop size decrease will bring about coalescence time decrease by enhancing the binary droplets oscillation. Moreover, there is an optimum interfacial tension to achieve the shortest coalescence time.
authors: College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, PR China. Electronic address: upclxm@163.com.
authors: Xiaoming
authors: X
authors: Luo
authors: College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, PR China.
authors: Juhang
authors: J
authors: Cao
authors: College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, PR China.
authors: Limin
authors: L
authors: He
authors: Qingdao Refinery Engineering Co., Ltd., CNOOC, Qingdao 266100, PR China.
authors: Hongping
authors: H
authors: Wang
authors: College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266580, PR China.
authors: Haipeng
authors: H
authors: Yan
authors: Mechanical and Chemical Engineering, The University of Western Australia, Crawley, WA 6151, Australia.
authors: Yahua
authors: Y
authors: Qin
keywords: Acoustic intensity; Binary droplets; Coalescence time; Interfacial tension; Ultrasonic standing waves