Smoothed particle hydrodynamics-based numerical investigation on sessile, oscillating droplets

Abstract

Forced oscillations in sessile droplets can be exploited in electrowetting mixing of fluid fractions. The necessary complex flows and large shape deformations require a numerical investigation of fluid dynamics in the transient regime. We provide a means to characterize oscillations qualitatively and quantitatively with the goal to examine and to classify flow patterns occurring inside. A superposition of different harmonic excitation patterns gives the possibility to control the convective flow. In this investigation, we apply a generic and accurate multi-phase smoothed particle hydrodynamics model to a twodimensional three-phase flow and consider an oscillating droplet sitting on a substrate and immersed in a fluidic phase. These vibrations are investigated in two ways: the analysis of a step response due to an abrupt change of the contact angle is applied to identify the resonance frequencies. Secondly, the time evolution of the shape of the droplet in terms of harmonic functions is determined. Their amplitudes are examined in the time and frequency domain. This gives the possibility to relate resonance frequencies to mode shapes and to detect a coupling between them. Our approach is successfully applied to different numerical case studies.

Modeling Solids in Nuclear Astrophysics with Smoothed Particle Hydrodynamics

“…Here, we will follow the idea of Weiß et al (2011) and represent the CCI in form of spherical harmonics, which are determined from SPH particle positions. The spherical harmonics representation will then be used to calculate the interface normal at the position of particles that are close to the CCI.…”

SYMPLER: SYMbolic ParticLE simulatoR with grid-computing interface

“…In all these cases particle dynamics was used for an SPH-simulation of the fluid dynamics of the moulded material. Further fluid dynamic applications of SYMPLER have been the simulation and design of electrowetting based microfluidic devices for the transportation of pico-to nanoliter droplets [46,47], constraint SPH-simulations of haemodynamics for the estimation of blood flow measurements with magnetic resonance imaging [48], and hydrodynamics with convective transport and dynamics of local magnetisation [49].…”

A Numerical Framework for Free Surface Flow and Wettability Based on Arbitrary Lagrange-Eulerian Method

“…The numerical results show the vortex structures inside the droplet in the movement and the oscillation of advancing angle and contact angle along with time. Wei et.a [12]l successfully study the stabilized shape of a droplet and its oscillation process through SPH (Smoothed Particle Hydrodynamics).…”