C5.3 - Common Challenges in Simulating the Fluid Dynamics of Electrowetting-On-Dielectrics Driven Devices

AMA Conferences 2017
2017-05-30 - 2017-06-01
Nürnberg, Germany
Proceedings Sensor 2017
C5 - Modeling and Simulation III
A. Tröls, B. Jakobya - Johannes Kepler University Linz (Austria)
372 - 375


Simulating fluid driven devices is a challenging task in terms of verifying the results provided by the solution algorithm. We particularly consider solvers based on the finite element method (FEM) provided by the commercial software COMSOL TM Multiphysics. The three-dimensional Navier-Stokes equations are highly dependent on the initial conditions and can only be solved numerically for particularly considered applications. Choosing a suitable solution algorithm is one of the main tasks
when working in the field of numerical fluid dynamics. For so-called Electrowetting-On-Dielectric (EWOD) driven systems, the main focus lies on interface tracking algorithms, like the well-known LevelSet or PhaseField method. The interfacial shape of a fluid in contact with another fluid or gas is governed by the equilibrium of their surface tensions. EWOD is a surface tension driven effect and so the correct reconstruction of the fluid interface is crucial for reliable FEM simulation results. Also the quality of the numerical mesh and its treatment during a movement of the fluid interface through the calculation area is essential. This work reviews the sensitivity of EWOD FEM simulation results on the chosen solver and gives simulation examples as well as a recommendation for the most suitable algorithm and numerical mesh settings. It also shows an example of the simulation results for scaling the fluid channel of an EWOD driven device, which was investigated recently, and the associated scaling limits obtained.