Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7057258 | International Journal of Heat and Mass Transfer | 2014 | 9 Pages |
Abstract
This study experimentally investigates non-uniform particle distributions and evaporation characteristics of nanofluid droplets containing 50Â nm average diameter alumina (Al2O3) particles, on a hydrophilic glass surface. Using an inverted microscope, the size distribution of aggregated nanoparticles was visualized and analyzed at different sight-of-view locations. From the digital images captured using CMOS cameras and a magnifying lens, the effect of particle concentrations on droplet evaporation rates was examined. In particular, in order to understand the significance of the early stage of droplet evaporation, the dynamics of a corresponding triple line were visualized using a high-speed imaging technique. From the results, it was found that as the volume fraction of nanoparticles in nanofluids increased the total evaporation time and the initial contact angle decreased, while the corresponding perimeter of the droplet increased. Local aggregation was observed when a nanofluid droplet was in contact on the surface, suggesting that the non-homogeneous characteristics should be considered in estimating thermal conductivity of a nanofluid droplet.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Dong Hwan Shin, Chang Kyoung Choi, Yong Tae Kang, Seong Hyuk Lee,