Article
Thermodynamics
Donghyun Seo, Jinsoo Park, Jaehwan Shim, Jeonghyeon Nam, Dong Hwan Shin, Youngsuk Nam, Jungho Lee
Summary: This study investigated the effects and limitations of a superhydrophobic (SHPo) surface in a two-phase closed thermosyphon (TPCT). The experiments revealed that at high heat fluxes, liquid collision led to flooding and decreased HTC, while at low heat fluxes, counter-current flow caused the entrainment of droplets and limited the condenser HTC.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Shangwen Gao, Suchen Wu, Raza Gulfam, Zilong Deng, Yongping Chen
Summary: In this study, a self-similar fractal groove superhydrophobic surface was designed and fabricated, and its droplet dynamics and heat transfer performance were investigated. The results showed that the fractal grooves can promote droplet jumping at low subcooling and facilitate condensate removal at high subcooling.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Suchen Wu, Shangwen Gao, He Wang, Zilong Deng
Summary: Inspired by the prickle tip of the cactus, researchers designed and fabricated a gradient groove superhydrophobic surface. They found that this surface exhibits the highest condensation heat flux among three superhydrophobic surfaces, even at higher subcooling, due to the synergistic effect of dual-Laplace induced jumping and gravity-driven sliding removal.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Tibin M. Thomas, Pallab Sinha Mahapatra
Summary: The study explores the fabrication of superhydrophobic surfaces and their performance during condensation phenomena in humid air. Different wetting behaviors and heat transfer coefficients were observed on the three distinct surfaces, suggesting potential applications in water-energy nexus.
Article
Thermodynamics
Xin Wang, Bo Xu, Qiusheng Liu, Yang Yang, Zhenqian Chen
Summary: Recently developed micro- or nano-structured surfaces have been used to enhance condensation heat transfer, water harvesting, and self-cleaning. However, condensate flooding at large subcoolings leads to decreased heat transfer efficiency. Superhydrophobic surfaces with micropillar and nanopillar structures have been proposed to improve heat transfer in such conditions. Experiments have shown that droplet dynamics and heat transfer performance are influenced by micropillar spacing and surface subcooling. Additionally, a microscopic modeling approach using the mesoscopic lattice Boltzmann method has been utilized to study condensation heat transfer on these surfaces. The results demonstrate that micropillared surfaces exhibit smaller droplet size distribution compared to nanostructured surfaces, but the heat transfer coefficient decreases with increased micropillar spacing. In high subcooling conditions, the S10R30 micropillar arrays have shown a 26.4% enhancement in heat transfer coefficient compared to hydrophobic nanostructured surfaces, due to the reduction in thermal resistance caused by the liquid film height being on the same order of magnitude as the micropillars.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Chemistry, Physical
Je-Un Jeong, Dae-Yun Ji, Kwon-Yeong Lee, Woonbong Hwang, Chang-Hun Lee, Sung-Jae Kim, Jeong-Won Lee
Summary: The study highlights the importance of superhydrophobic surfaces being able to resist attached condensation in supersaturated conditions to improve heat transfer efficiency, which can be achieved by controlling the gap size and complexity of micro/nanoscale surface structures to maintain water repellency.
Article
Thermodynamics
Xin Wang, Bo Xu, Zhenqian Chen
Summary: A new hierarchical superhydrophobic surface with micropores and nanoblades (MN SHS) is proposed to enhance the jumping ability of droplets and maintain high-efficiency droplet jumping condensation at larger subcoolings. The results show that MN SHS has a higher jumping frequency and a higher proportion of multidroplets merging compared to nanostructured superhydrophobic surfaces (Nano SHS). The maximum diameter of condensate droplets on MN SHS is 50% smaller than that on Nano SHS.
APPLIED THERMAL ENGINEERING
(2023)
Review
Chemistry, Multidisciplinary
Navdeep Sangeet Singh, Jitao Zhang, Jason Stafford, Carl Anthony, Nan Gao
Summary: Steam condensation is unavoidable in industrial processes, but using liquid repellent surfaces can improve heat transfer efficiency, save costs, and reduce emissions. However, challenges remain, particularly in stabilizing liquid repellent surfaces at large subcooling temperatures and high supersaturation ratios.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Physics, Multidisciplinary
Henry Lambley, Gustav Graeber, Raphael Vogt, Leon C. C. Gaugler, Enea Baumann, Thomas M. M. Schutzius, Dimos Poulikakos
Summary: Supercooled droplet freezing on surfaces is a common phenomenon in nature and industry, but little is known about its effect on droplet-substrate interactions and the design of icephobic surfaces. This study investigates freezing of supercooled droplets on textured surfaces and identifies surface properties that promote ice expulsion. The study also explores mechanisms through which repellency falters and provides insights into the phenomenology of ice adhesion throughout freezing. The findings contribute to the design of icephobic surfaces for increased safety and sustainability in engineering applications.
Article
Engineering, Chemical
Nataliia Fedorova, Christian Lindner, Lucia Helena Prado, Vojislav Jovicic, Ana Zbogar-Rasic, Sannakaisa Virtanen, Antonio Delgado
Summary: The jumping-droplet phenomenon on superhydrophobic surfaces can increase heat transfer coefficients. Steam condensation experiments on samples with varying storage periods showed that higher steam flow rates led to coating damage and changes in water contact angles.
Article
Physics, Applied
Muhammad Jahidul Hoque, Jingcheng Ma, Kazi Fazle Rabbi, Xiao Yan, Bakhshish Preet Singh, Nithin Vinod Upot, Wuchen Fu, Johannes Kohler, Tarandeep Singh Thukral, Sujan Dewanjee, Nenad Miljkovic
Summary: This article discusses the recent advancements and challenges in the development of durable superhydrophobic surfaces, highlighting its potential impact on global energy production, water conservation, and reducing carbon footprint.
APPLIED PHYSICS LETTERS
(2023)
Article
Thermodynamics
Zilong Deng, Shangwen Gao, He Wang, Xiangdong Liu, Chengbin Zhang
Summary: This paper investigates the condensation behavior and heat transfer characteristics of humid air on vertical surfaces with wettability gradient. The results show that the traditional gradient surface performs better than the hydrophilic case but worse than the hydrophobic case. Therefore, a periodic gradient surface is introduced to improve the condensation heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Eric D. Lee, Daniel Maynes, Julie Crockett, Brian D. Iverson
Summary: This paper presents an experimental study on drop impingement and thermal atomization on hydrophobic and superhydrophobic surfaces. The results show that superhydrophobic surfaces can completely suppress atomization and the maximum atomization temperature as well as the time of maximum atomization are both related to the parameters of the superhydrophobic surfaces.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Xu Chen, Yi-Feng Wang, Yan-Ru Yang, Xiao-Dong Wang, Duu-Jong Lee
Summary: This study investigates the impact of adding ridges to a superhydrophobic cylindrical surface on contact times. It found that at ultralow and medium Weber numbers, the ridges result in longer contact times, while at high Weber numbers, the liquid film above the ridges ruptures, leading to shorter contact times. The study also introduced a criterion, where a value exceeding 2.42 indicates shorter contact times that decrease further with increasing Weber numbers or decreasing droplet diameter.
Article
Construction & Building Technology
Ziwen Zhong, Wei Ma, Shuhuai Yao, Xiangguo Xu, Jianlei Niu
Summary: This study estimated the enhanced cooling capacity of radiant ceiling panels (RCP) through latent heat transfer. Experimental results confirmed that the condensation heat transfer of a superhydrophobic aluminum surface can be predicted using the heat and mass transfer analogy method. The total heat flux of RCP with latent heat transfer was found to increase by 3% to 500% compared to RCP with only sensible cooling.
ENERGY AND BUILDINGS
(2022)
