On the migration of a droplet on an incline

Qingwen Dai; M M Khonsari; Cong Shen; Wei Huang; Xiaolei Wang

doi:10.1016/j.jcis.2017.01.055

On the migration of a droplet on an incline

J Colloid Interface Sci. 2017 May 15:494:8-14. doi: 10.1016/j.jcis.2017.01.055. Epub 2017 Jan 18.

Authors

Qingwen Dai¹, M M Khonsari², Cong Shen³, Wei Huang⁴, Xiaolei Wang¹

Affiliations

¹ College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China; Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology, Nanjing 210016, China.
² Department of Mechanical and Industrial Engineering, Louisiana State University, 3283 Patrick Taylor Hall, Baton Rouge, LA 70803, USA. Electronic address: khonsari@me.lsu.edu.
³ Department of Mechanical and Industrial Engineering, Louisiana State University, 3283 Patrick Taylor Hall, Baton Rouge, LA 70803, USA.
⁴ College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China.

PMID: 28131033
DOI: 10.1016/j.jcis.2017.01.055

Abstract

A liquid droplet placed on a nonuniformly heated solid surface will migrate from a high temperature region to a low temperature region. The present study reports the results of an experimental investigation on the migration behavior of mineral oil droplets subjected to a thermal gradient on an inclined plane. A particular attention is paid to the relationship between the critical inclination angle and thermal gradients. It is shown that there exists a critical inclination angle at which the droplet migration is halted. This critical inclination angle can be readily predicted using analytical expressions derived in this paper. This study puts forward the understanding of the interface phenomenon of thermocapillary migration on an incline. The knowledge of the critical inclination is important in applications where the migration on an incline must be obstructed to retain adequate lubrication in the desired location.

Keywords: Inclination angle; Lubrication approximation; Surface tension; Thermocapillary migration.

Publication types

Research Support, Non-U.S. Gov't