Session: 10.2.3 - Interfacial Phenomena and Flows III

Paper Number: 158049

158049 - A Numerical Investigation on the Effect of Contact-Line Mobility on Sessile Drop Oscillation Dynamics 

Abstract: 

The present study numerically investigates the effect of contact-line mobility on the oscillation of a sessile drop on a flat surface with varying contact angles. The volume-of-fluid method is employed to capture the sharp interface, while the height-function method is used to calculate interface curvature and specify the contact angle on the solid surface. A hyperbolic tangent dynamic contact angle model relates the contact angle to the contact line velocity. A key feature of this model is the contact-line mobility parameter, which quantifies the degree of contact line hysteresis. The two asymptotic limits of contact-line mobility are the free contact line (FCL), where the contact angle remains constant as the contact line moves, and the pinned contact line (PCL), where the contact line remains fixed while the contact angle varies freely.

Parametric simulations are conducted for different contact angles and levels of contact-line mobility to systematically examine their effects on oscillation frequency and decay rate. The results reveal that the frequency of the dominant mode increases monotonically with contact-line mobility. In contrast, the decay rate exhibits non-monotonic behavior as contact-line mobility changes, with a critical value of contact-line mobility leading to the fastest decay of oscillation amplitude. These simulations provide valuable insights into the contributions of contact-line dissipation and viscous dissipation, which are crucial for understanding the variation in decay rates.

Presenting Author: Sadegh Ahmadi University of South Carolina

Presenting Author Biography: