Pattern geometry optimization on superbiphilic aluminum surfaces for enhanced pool boiling heat transfer

Matic Može (Author), Matevž Zupančič (Author), Iztok Golobič (Author)

Abstract

In this study, the optimal surface pattern of low and high wettability regions for enhanced boiling heat transfer is investigated using aluminum superbiphilic surfaces. Samples are fabricated by combining chemical vapor deposition of a fluorinated silane to turn them superhydrophobic and nanosecond laser texturing to render selected areas superhydrophilic. Triangular lattice pattern of superhydrophobic circular spots is utilized with spot diameters between 0.25 mm and 1.0 mm and pitch values of 0.5-2.5 mm. Pool boiling heat transfer performance of superbiphilic surfaces is evaluated using saturated water at atmospheric pressure. A strong wettability contrast is shown to be important in ensuring high heat transfer performance of wettability-patterned surfaces. Highest heat transfer performance is achieved using 0.5 mm diameter spots with a spot pitch of 1 mm and a corresponding superhydrophobic area fraction of approx. 23%. The optimal pitch value will provide a high density of potentially active nucleation sites but still allow for the development of the thermal boundary layer thus not inhibiting the activation of neighboring spots. The size of (super)hydrophobic spots appears not to have a major influence on the boiling performance when using the optimal spot pitch. The developed superbiphilic surfaces increase the CHF and provide greatly enhanced heat transfer coefficients especially at medium and high heat fluxes, making them suitable especially for high-heat-flux applications.

Keywords

prenos toplote;vrenje v bazenu;mehurčkasto vrenje;bifilne površine;inženiring površin;heat transfer;pool boiling;nucleate boiling;biphilic surfaces;surface engineering;

Data

Language:	English
Year of publishing:	2020
Typology:	1.01 - Original Scientific Article
Organization:	UL FS - Faculty of Mechanical Engineering
UDC:	536.24(045)
COBISS:	25544963
ISSN:	0017-9310
Views:	1411
Downloads:	601
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	prenos toplote;vrenje v bazenu;mehurčkasto vrenje;bifilne površine;inženiring površin;kritični toplotni tok;funkcionalizacija površin;izboljšanje prenosa toplote;
Type (COBISS):	Article
Pages:	f. 1-13
Issue:	ǂVol. ǂ161
Chronology:	Nov. 2020
DOI:	10.1016/j.ijheatmasstransfer.2020.120265
ID:	11963994