Copper-based superhydrophobic nanostructures for heat transfer in flow condensation

Mohammadpour Chehrghani, Mirvahid and Abbasiasl, Taher and Sadaghiani, Abdolali Khalili and Koşar, Ali (2021) Copper-based superhydrophobic nanostructures for heat transfer in flow condensation. ACS Applied Nano Materials, 4 (2). pp. 1719-1732. ISSN 2574-0970

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Superhydrophobic surfaces enhance the condensation heat transfer performance by facilitating removal of condensed droplets and coalescence-induced droplet jumping. During the last decade, studies on superhydrophobic surfaces have been mostly limited to working conditions, which are ideal for electron microscopy techniques. Therefore, the behavior of condensed droplets in the presence of a vapor flow with different vapor qualities and their implementation in flow condensation heat transfer enhancement have received rather little attention, which is the motivation behind this study. Thus, beside heat transfer analysis, we performed a visualization study on flow condensation in a minichannel and investigated droplet dynamics, including a histogram of droplet diameter distribution at different time intervals and stages of a condensation cycle consisting of nucleation growth and departure, droplet departure diameters, cycle time, and droplet number density. The droplet departure diameter decreases with steam mass flux, leading to a shift to smaller radii in droplet size distribution, which enhances condensation heat transfer. Enhancements up to 33% in the heat transfer coefficient were obtained at lower steam qualities for the tested superhydrophobic surface compared to the reference plain hydrophobic surface. We demonstrated that in addition to the high vapor shear stress exerted by the flow on the interface of the vapor and the condensed droplet, the advantage of an inherently unique water repellency feature of the nanostructured superhydrophobic surface can be utilized in flow condensation for enhancing condensation heat transfer.
Item Type: Article
Uncontrolled Keywords: flow condensation, droplet distribution, superhydrophobic surface, nanostructured surface, droplet condensation heat transfer, minichannel
Subjects: T Technology > TJ Mechanical engineering and machinery
T Technology > TP Chemical technology > TP0155-156 Chemical engineering
Divisions: Center of Excellence on Nano Diagnostics
Faculty of Engineering and Natural Sciences > Academic programs > Mechatronics
Sabancı University Nanotechnology Research and Application Center
Faculty of Engineering and Natural Sciences
Depositing User: Abdolali Khalili Sadaghiani
Date Deposited: 22 Aug 2021 12:21
Last Modified: 03 Sep 2022 13:18

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