Droplet retention on an incline

S. Ravi Annapragada, United Technol Res Ctr
Jayathi Y. Murthy, Birck Nanotechnology Center, Purdue University
Suresh V. Garimella, Birck Nanotechnology Center, Purdue University

Date of this Version



International Journal of Heat and Mass Transfer Volume 55, Issues 5–6, February 2012, Pages 1457–1465


The present study seeks to understand and predict droplet retention on smooth hydrophobic surfaces. The droplet shape and the advancing and receding contact angles are experimentally measured as a function of droplet size under the action of a gravitational force at different inclination angles. The advancing and receding contact angles are correlated with static contact angle and Bond number. A Volume of Fluid Continuous Surface Force model with varying contact angles along the triple contact line is developed to predict droplet shape. The model is first verified against a two dimensional analytical solution. It is then used to simulate the shape of a sessile droplet on an incline at various angles of inclination and to determine the critical angle of inclination as a function of droplet size. Good agreement is found between experimental measurements and predictions. The contact line profile and contact area are also predicted. The contact area predictions based on a spherical-cap assumption are compared to the numerical predictions and are found to underpredict the droplet contact area. (C) 2011 Elsevier Ltd. All rights reserved.


Nanoscience and Nanotechnology