Coalescence-induced jumping of microdroplets on superhydrophobic surfaces – A numerical study
Artikel i vetenskaplig tidskrift, 2022

We develop a numerical framework for simulating the coalescence and jumping of microdroplets on superhydrophobic surfaces. The framework combines the VOF method with models for advancing and receding contact angles on a number of superhydrophobic surfaces. We demonstrate the temporal and spatial convergence of the framework and show agreement between our numerical results and other experimental studies. The capillary-inertial scaling is investigated together with the existence of a cut-off behaviour frequently observed in the lower size-range of that regime. We investigate findings in some of the previous studies that the cut-off behaviour can be attributed to viscosity effects and dissipation due to interaction with surface microstructures. We exemplify specific features related to the jumping process and the corresponding energy budget analysis when microdroplets coalesce and jump. We have tested droplets of a radius as small as 0.5 μm that are still jumping but recorded a decrease in the jumping velocity and the degree of energy conversion compared to the jumping of larger droplets. We argue and prove that strong capillary forces originating from the high curvature oscillations dissipate the energy of the system significantly faster in the case of microdroplets.

contact angle

VOF–Immersed boundary

wetting

microdroplets

Författare

Konstantinos Konstantinidis

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Johan Göhl

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Andreas Mark

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Srdjan Sasic

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Canadian Journal of Chemical Engineering

0008-4034 (ISSN) 1939019x (eISSN)

Vol. 100 12, Special Issue Article 3517-3530

Uppnystning av hur, när och varför i självframdrivna och självupprätthållna partikelbaseradesjälvrengöringsmekanismer på superhydrofoba ytor

Vetenskapsrådet (VR) (2019-04969), 2020-01-01 -- 2024-12-31.

Ämneskategorier

Teknisk mekanik

Annan fysik

Annan materialteknik

Strömningsmekanik och akustik

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1002/cjce.24591

Mer information

Senast uppdaterat

2022-11-07