Local heat transfer to an evaporating superhydrophobic droplet. (June 2018)

• Record Type: Journal Article
• Authors: Gibbons, M.J.; Di Marco, P.; Robinson, A.J.
• Is Part Of: International journal of heat and mass transfer. Volume 121(2018)
• Page Start: 641
• Page End: 652
• Publication Date: 2018-06
• Subjects: Droplet -- Evaporation -- Heat transfer -- Contact line -- Superhydrophobic; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2018.01.007
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Local heat transfer to a superhydrophobic evaporating droplet. Infrared thermography and optical imaging employed in characterising evaporation. Droplet heat flux increased with increasing CLD and liquid-gas interface temperature. Thermal power dissipated decreases due to decreasing wetted area. Average droplet heat flux proportional to the contact line length density. Abstract: The heat flux distribution beneath a superhydrophobic evaporating droplet has been explored. High speed, high resolution infrared thermography was employed to measure the heat transfer characteristics of the evaporating droplet. Optical imaging and analytical techniques were used the capture droplet dynamics over the course of its evaporation. The droplet evaporated with a receding contact line predominantly in the constant contact angle regime. The peak local convective heat transfer was located at the triple contact line over the entire evaporation period. Peak and average heat fluxes were shown to increase as the evaporation proceeded due to the increasing contact line length density and liquid-gas interface temperature. The total thermal power across the solid-liquid interface decreased due to the decreasing solid-liquid surface area. The average heat flux to the evaporating droplet was shown to vary linearly with contact line length density.