Prediction of Contact Angle of Nanofluids by Single-Phase Approaches†
1
Graduate School of Natural and Applied Sciences, İzmir Kâtip Çelebi University, 35620 İzmir, Turkey
2
Institut für Luft- und Kältetechnik gGmbH Dresden, 01309 Dresden, Germany
3
Department of Mechanical Engineering, İzmir Kâtip Çelebi University, 35620 İzmir, Turkey
4
Univ Rennes, LGCGM, EA3913, F-35000 Rennes, France
5
Departamento de Ingeniería Mecánica y Construcción, Universitat Jaume I, 12071 Castelló de la Plana, Spain
*
Authors to whom correspondence should be addressed.
†
This article is an extended version of our paper published in 1st International Conference on Nanofluids (ICNf) and 2nd European Symposium on Nanofluids (ESNf), Castellón, Spain, 26–28 June 2019; pp. 162–166.
Energies 2019, 12(23), 4558; https://doi.org/10.3390/en12234558
Received: 30 October 2019 / Revised: 22 November 2019 / Accepted: 27 November 2019 / Published: 29 November 2019
(This article belongs to the Special Issue Selected papers of the "1st International Conference on Nanofluids (ICNf)")
Wettability is the ability of the liquid to contact with the solid surface at the surrounding fluid and its degree is defined by contact angle (CA), which is calculated with balance between adhesive and cohesive forces on droplet surface. Thermophysical properties of the droplet, the forces acting on the droplet, atmosphere surrounding the droplet and the substrate surface are the main parameters affecting on CA. With nanofluids (NF), nanoparticle concentration and size and shape can modify the contact angle and thus wettability. This study investigates the validity of single-phase CA correlations for several nanofluids with different types of nanoparticles dispersed in water. Geometrical parameters of sessile droplet (height of the droplet, wetting radius and radius of curvature at the apex) are used in the tested correlations, which are based on force balance acting on the droplet surface, energy balance, spherical dome approach and empirical expression, respectively. It is shown that single-phase models can be expressed in terms of Bond number, the non-dimensional droplet volume and two geometrical similarity simplexes. It is demonstrated that they can be used successfully to predict CA of dilute nanofluids’ at ambient conditions. Besides evaluation of CA, droplet shape is also well predicted for all nanofluid samples with ±5% error.
View Full-Text
Keywords:
contact angle; nanofluid; Bond number
▼
Show Figures
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Çobanoğlu, N.; Karadeniz, Z.H.; Estellé, P.; Martínez-Cuenca, R.; Buschmann, M.H. Prediction of Contact Angle of Nanofluids by Single-Phase Approaches. Energies 2019, 12, 4558.
Show more citation formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.