Motion of Ferrofluid Drops in a Rotational Magnetic Field

• Main Authors: Peng, Wen-Zhi, 彭文志
• Other Authors: Chen, Ching-Yao
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/es76wa

碩士 === 國立交通大學 === 機械工程系所 === 108 === This study investigates how the initial diameter between two droplets in immiscible fluids affects the rotation type. The experiment put magnetic fluid together with non-magnetic fluid, and use plane revolving magnetic field to create tensile effect on the droplets. As the magnetic field was added, the shape of the droplet changes from circle into ellipse. This study changes the initial diameter and distance between two magnetic droplets, and there are four types of motion being observed: self-spin, dual rotation, rigid rotation and coalescence. Self-spin possesses the longest initial distance, and the angular acceleration of rigid rotation is higher than dual rotation. In this study, the initial diameter and distance between two droplets, angular velocity and angular acceleration and radial velocity are combined to get dimensionless parameters such as Weber number, Capillary number, Bond number, Laplace number and DL, and are plotted into a dimensionless diagram. Since droplet motion cannot be discriminated from the dimensionless plot, so in order to find the diagram able to differentiate the four motions, diagram between angular acceleration and D/L were plotted for further study.