Information Services banner Edinburgh Research Archive The University of Edinburgh crest

Edinburgh Research Archive >
Engineering, School of >
Engineering, School of >
Engineering thesis and dissertation collection >

Please use this identifier to cite or link to this item: http://hdl.handle.net/1842/5296

This item has been viewed 88 times in the last year. View Statistics

Files in This Item:

File Description SizeFormat
Moffat2011.pdf3.58 MBAdobe PDFView/Open
Title: Experimental investigation into the evaporating behaviour of pure and nanofluid droplets.
Authors: Moffat, John Ross
Supervisor(s): Sefiane, Khellil
Easson, Bill
Issue Date: 28-Jun-2011
Publisher: The University of Edinburgh
Abstract: In this experimental investigation the evaporative behaviour of liquid droplets of both pure fluids and fluids containing nanoparticles was studied. Initial tests were conducted on drops of pure volatile liquids using IR thermography, and the effect of substrate material, drop composition, and substrate temperature was investigated. The effect of the addition of nanoparticles to the liquid drops was then investigated using a contact angle analyser which could record the drop profile in time. The effects of liquid composition, nano-particle composition, nanoparticles concentration, substrate hydrophobicity, and substrate temperature were all studied. Results obtained from IR thermography showed that there exists interfacial temperature instabilities in evaporating volatile drops, the appearance of these fluctuations was found to be dependent on the liquid and substrate in question and are self generated temperature gradients resulting from non-uniform evaporation. A stability analysis was conducted and the results give a good agreement with experimental results. The addition of nanoparticles to a liquid drop was found to alter the evaporative behaviour by enhancing pinning of the drop contact line and preventing the drop radius from shrinking. By manipulating the concentration of the particles suspended in a drop, a stick-slip evaporative process was achieved, leading to rings of particulate material formed upon total evaporation. By varying parameters such as substrate hydrophobicity, nanoparticle concentration, liquid composition, and substrate temperature, many distinct nanoparticle deposit patterns were observed upon total evaporation. It was shown that by varying these parameters, many different patterns could be achieved, and that inside these deposit patterns regular formations such as particulate rings, radial lines, and cellular structures were present.
Sponsor(s): Engineering and Physical Sciences Research Council (EPSRC)
Keywords: drop
nanofluid
evaporation
particles
URI: http://hdl.handle.net/1842/5296
Appears in Collections:Engineering thesis and dissertation collection

Items in ERA are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Valid XHTML 1.0! Unless explicitly stated otherwise, all material is copyright © The University of Edinburgh 2013, and/or the original authors. Privacy and Cookies Policy