Article
Chemistry, Multidisciplinary
Fuqiang Chu, Xiao Yan, Nenad Miljkovic
Summary: This study investigates the mechanism of droplet shedding from superhydrophobic grooves and its dependence on surface and droplet configurations through simulations and visualizations. The role of Laplace pressure in governing single-droplet jumping is verified, and an optimized departure velocity is obtained. The findings of this study provide important guidance for designing interfaces and materials to enhance microdroplet shedding in various applications.
Article
Mechanics
Biao Huang, Xiwen Zhang, Xiangru Li, Haixiang Zhang, Feng He, Pengfei Hao, Zhaohui Yao
Summary: This paper investigates droplet condensation and self-propelled jumping on microcolumn-structured superhydrophobic surfaces with different size parameters using a three-dimensional multiphase lattice Boltzmann method. A new phenomenon of secondary coalescence jumping is identified, and its underlying mechanisms are analyzed in detail. The results show that wettability and structure parameters have significant effects on droplet jumping.
Article
Chemistry, Multidisciplinary
Xifan Fu, Qinpeng Zhu, Denghui Liu, Binghan Liu, Lintao Kuang, Yanhui Feng, Fuqiang Chu, Zhi Huang
Summary: A study on moisture condensation on hybrid superhydrophobic-hydrophilic surfaces revealed the significant impact of wettability difference and microstructure size on condensation efficiency, leading to a 90% enhancement in condensation rate. Detailed analysis of the condensation process provided insights into the enhanced condensation mechanism, proposing effective methods for controlling and optimizing moisture condensation.
Article
Chemistry, Multidisciplinary
Chuntian Liu, Meirong Zhao, Dunqiang Lu, Yukai Sun, Le Song, Yelong Zheng
Summary: Coalescence-induced droplet jumping has great prospects in many applications but is hindered by a low jumping velocity. This study presents rationally designed limitation structures with superhydrophobic surfaces to achieve a higher jumping velocity. Through experimental and numerical analysis, the mechanism of enhancing the jumping velocity is explained and a method combining limitation structures with protruding structures is proposed to further improve the jumping velocity.
Article
Chemistry, Multidisciplinary
Kai Wang, Xuehu Ma, Feifan Chen, Zhong Lan
Summary: The study systematically investigates the effect of structural parameters of the triangular prism on droplet jumping velocity on superhydrophobic surfaces. Results show that exploiting structure effects can greatly increase droplet jumping velocity, with the optimal length of the triangular prism reaching a plateau. The ratio of translational kinetic energy to released surface energy during droplet jumping is determined by the apex angle and height of the triangular prism, being more effective with a smaller apex angle and a larger height.
Article
Chemistry, Multidisciplinary
Yihao Zhu, Tsz Chung Ho, Hau Him Lee, Michael Kwok Hi Leung, Chi Yan Tso
Summary: By optimizing the structure of a biphilic surface, the condensation performance can be improved. A experimentally verified theory of droplet jumping is reported, which can maximize the jumping height of droplets on the biphilic surface. The improved biphilic surface shows significantly enhanced heat flux and water collection efficiency.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Muhammad Jahidul Hoque, Shreyas Chavan, Ross Lundy, Longnan Li, Jingcheng Ma, Xiao Yan, Shenghui Lei, Nenad Miljkovic, Ryan Enright
Summary: The combination of smooth, low-surface-energy spots with rough superhydrophobic backgrounds can achieve higher jumping-droplet condensation heat-transfer coefficients. Design guidelines for biphilic surfaces to maximize condensation heat transfer are proposed based on simulation and experimental validation.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Chemistry, Physical
Lianfu Qiu, Sheng Qian, Yifeng Ni, Qi Tong
Summary: When droplets coalesce on a superhydrophobic surface, the converted kinetic energy enables them to jump. Our molecular dynamics study focuses on coalescence-induced jumping of nanodroplets on soft substrates. We suggest the optimum substrate stiffness and analyze the interactions involved to evaluate the droplets' momentum. The competition between impact and adhesion determines the optimum stiffness for jumping velocity. These results may inspire further research and applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Mechanics
K. Konstantinidis, J. Gohl, A. Mark, S. Sasic
Summary: This article investigates the coalescence and jumping behavior of droplets on superhydrophobic surfaces, with a focus on the influence of contact-angle hysteresis. A comprehensive numerical framework is developed, which considers the effect of hysteresis by accurately representing the contact angles. The results demonstrate the impact of hysteresis on the jumping process and identify different stages of droplet detachment and re-attachment. The study also highlights the importance of accurately capturing the dynamic receding contact angle when droplets jump from superhydrophobic surfaces with varying degrees of hysteresis.
Article
Mechanics
Sihang Gao, Zhifeng Hu, Xiaomin Wu
Summary: This study demonstrates that the horizontal mobility of coalesced droplets on superhydrophobic surfaces with an asymmetric ridge can be enhanced, leading to promoted droplet jumping. Experimental results show that the coalesced droplet accelerates during the jumping stage and gains horizontal velocity during the rebound stage, reaching a nondimensional horizontal velocity of 0.47, which is about 2.3 times the jumping velocity on the plane.
Article
Mechanics
Huimin Hou, Zhiping Yuan, Zhifeng Hu, Sihang Gao, Xiaomin Wu
Summary: With the development of superhydrophobic surface technology, coalescence-induced droplet jumping has broad applications in condensation heat transfer and self-cleaning. This study examines the process of droplet jumping induced by coalescence on superamphiphobic surfaces using glycerol-water mixtures with different glycerol volume fractions. Results indicate that the effects of surface tension gradient and viscosity on droplet jumping differ in different regions.
Article
Chemistry, Multidisciplinary
Yu Tang, Xiaolong Yang, Yimin Li, Yao Lu, Di Zhu
Summary: The study designed micropapillaes overlaid with nanograss to enhance dropwise condensation efficiency, delay flooding, and increase heat transfer coefficient. Furthermore, the micropapillaes acted as forts protecting the nanograss, improving the surface mechanical and chemical robustness.
Article
Mechanics
Shi Tang, Qing Li, Yue Yu
Summary: In this paper, droplet jumping on V-shaped groove superhydrophobic surfaces induced by coalescence was numerically investigated using a three-dimensional multiphase lattice Boltzmann model. It was found that the self-jumping process becomes inefficient as the groove angle decreases due to increased viscous dissipation. An improved V-shaped superhydrophobic surface with a triangular prism was proposed to enhance droplet jumping performance. Numerical results showed significantly increased jumping velocity and energy conversion efficiency, up to 80% and 210% respectively, compared to the surface without the triangular prism. The enhancement was attributed to the redirection of the expanding liquid bridge by the V-shaped sidewalls and the earlier and sufficient impact of the liquid bridge on the triangular prism in the groove. The improved V-shaped superhydrophobic surface also allowed for guided jumping and more accurate prediction of the jumping angle based on the groove angle.
Article
Multidisciplinary Sciences
Chen Ma, Li Chen, Lin Wang, Wei Tong, Chenlei Chu, Zhiping Yuan, Cunjing Lv, Quanshui Zheng
Summary: In this study, a technique called condensation droplet sieve is developed to control the size and distribution of large droplets. By fabricating special lattice structures, the growing droplets can detach automatically once they reach a certain size, thus improving the anti-fogging and heat transfer properties of the material.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Zhiping Yuan, Sihang Gao, ZhiFeng Hu, Liyu Dai, Huimin Hou, Fuqiang Chu, Xiaomin Wu
Summary: The study proposed enhanced jumping methods for droplets on superhydrophobic surfaces, which achieved a nearly theoretical limit of energy transfer efficiency through more orderly flow inside the droplets enabled by a designed structure. The ultimate jumping improved the application of water droplet jumping and enabled other low surface energy fluids to jump.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Xinyuan Liu, Li Jia, Jinzhu Xu, Chao Bang, Yi Ding
Summary: This study explores the regulatory mechanism of additional momentum force from microporous airflow on the wettability and dynamic behavior of low surface energy droplets. By using microporous airflow, droplets can achieve quasi-superhydrophobic levitation state without additional components or special requirements. This method provides a new approach for low surface tension droplet manipulation.
CHINESE SCIENCE BULLETIN-CHINESE
(2021)
Article
Thermodynamics
Zhuo Cui, Li Jia, Zhou Wang, Chao Dang, Liaofei Yin
Summary: This paper presents an ultra-thin flat heat pipe (UTFHP) with small thickness and high thermal performance for the thermal management of high-performance electronic devices. The effects of fill ratio, mesh number, and passage width on the thermal resistance and temperature distribution of UTFHPs are analyzed, and the optimal thermal performance is achieved under specific conditions.
APPLIED THERMAL ENGINEERING
(2022)
Article
Chemistry, Physical
Yi Ding, Li Jia, Liaofei Yin, Chao Dang, Xinyuan Liu, Jinzhu Xu
Summary: The anisotropic wetting characteristics of droplets on micro-grooved surfaces were studied through experiments and simulations. The results showed that gravity played an important role in affecting droplet wetting behavior without inducing collapse of the Cassie-Baxter state. The spreading stage of the deposited droplets was dominantly influenced by capillary forces, and anisotropic wetting characteristics were evident with differences in droplet base length and contact angle in different directions.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Thermodynamics
Ren Honglei, Jia Le, Dang Chao, Yang Chengliang, Jia Hongyang, Liu Junjie
Summary: An electrochemical thermal coupling model of a lithium battery was established to study its heat generation characteristic. The simulation results showed that the heat generation density of the battery increased with the discharge rate, and the heat generation density was not uniform in different areas. By designing the mini-channels in the cooling plate, temperature non-uniformity can be improved and the cooling performance can be enhanced.
JOURNAL OF THERMAL SCIENCE
(2022)
Article
Energy & Fuels
Honglei Ren, Li Jia, Chao Dang, Zhuoling Qi
Summary: In this study, an electrochemical thermal coupling model was established to simulate the discharge process of a prismatic lithium battery. The study found that the heat generation distribution in the porous electrodes was non-uniform and the negative electrode played a dominant role in the porous area. Furthermore, the relationship between total heat generation, discharge time, and discharge rate was proposed.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Chemistry, Physical
Xiaowei Wang, Li Jia, Chao Dang
Summary: Hydrophobic surfaces are widely used due to their excellent properties. This study investigates the wetting behavior of droplets on reentrant microstructure surfaces using numerical simulations. The results show that the reentrant structure can effectively inhibit wetting transition and maintain a large apparent contact angle. The geometric parameters of the reentrant structure have a significant impact on the wetting behavior.
COLLOID AND INTERFACE SCIENCE COMMUNICATIONS
(2022)
Article
Thermodynamics
Liaofei Yin, Mingmei Sun, Peixue Jiang, Chao Dang, Li Jia
Summary: This study demonstrates that the use of a porous substrate in open microchannel heat sinks can greatly improve the heat transfer performance and prevent local dryout. In the high heat flux region, the flow boiling heat transfer coefficient remains stable with increasing heat flux in the porous open microchannels.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Physical
Yi Ding, Li Jia, Liaofei Yin, Chao Dang, Xinyuan Liu, Jinzhu Xu
Summary: The anti-gravity self-climbing behavior of a barrel-shaped droplet with low surface tension on a vertical conical surface was studied. Analytic expressions of the gas-liquid interface were established, and the positions of the advancing and receding ends were numerically determined. The results showed that the droplets exhibited increased apparent dynamic contact angles with volume, and the highest self-climbing height of the droplet increased with decreasing surface tension. The presence of a pre-wetting film on the conical surface reduced the contact line pinning force, facilitating the self-climbing of the droplet when the pinning force dominated over gravity. Compared to other interface shapes, the parabolic shape provided more accurate predictions of droplet thickness and self-climbing height, with relative differences of less than 20% between theoretical and experimental results. The findings have significant implications for manipulating low surface tension droplets in various applications.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Multidisciplinary
Xinyuan Liu, Li Jia, Yi Ding, Xiaowei Wang, Jinzhu Xu
Summary: The manipulation of droplet impact behavior on an asymmetric surface structure has great potential in various fields. However, there is a lack of research in predicting the dynamics of small-volume droplets on asymmetric superhydrophobic surfaces. In this study, a curved micropillar array surface with control-lable bending angles was prepared and the impact and rebound behaviors of nanoliter droplets were investigated. Experimental results showed correlations between droplet impact morphology and micropillar inclination angle, as well as nonmonotonic dependence of the restitution coefficient on Weber number.
Article
Immunology
Ting Liu, Ming Zheng, Li Jia, Mingyuan Wang, Longhai Tang, Zhenke Wen, Miaojia Zhang, Fenghong Yuan
Summary: Elevated circulating leptin levels in SLE patients are inversely associated with disease activity. Leptin inhibits Tfh cell differentiation through AMPK activation. Leptin receptor deficiency in SLE patients impairs the inhibitory effect of leptin on Tfh cell differentiation, resulting in the coexistence of high leptin levels and increased Tfh cell frequencies in SLE patients.
FRONTIERS IN IMMUNOLOGY
(2023)
Article
Thermodynamics
Honglei Ren, Liaofei Yin, Chao Dang, Ruming Liu, Li Jia, Yong Ding
Summary: In this study, a liquid phase-change cooling module with mini-channels cold plate was designed. The temperature properties of a battery monomer with different cooling conditions and varying discharge rates were investigated. The heat dissipation contribution of latent heat transfer to the overall cooling performance of the mini-channels cold plate was analyzed based on the outlet vapor quality. A cooling strategy with varying coolant flow rates was proposed and examined at 3C discharge rate. The findings showed that the proposed variable flow cooling strategy could efficiently reduce the coolant consumption and the pump power consumption of the BTMS while providing the same or even superior cooling performance, thereby assisting the optimization of the BTMS and serving as a reference for the application of the varying flow rate cooling strategy in actual engineering.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Psychology, Multidisciplinary
Li Jia, Zhikun Liang, Chuanping Lei, Li Huang
Summary: This research applies organizational knowledge management principles to college student groups in universities, exploring the relationship between knowledge-sharing behaviors, group performance, and individual social status. The study of 497 college students in China reveals that individual knowledge-sharing behavior influences others' behavior and recognition, and others' behavior contributes to group performance. The study emphasizes the importance of effective knowledge sharing practices for student management in higher education institutions.
FRONTIERS IN PSYCHOLOGY
(2023)
Article
Thermodynamics
H. Zhang, L. Jia, L. S. Cui, C. H. Li
Summary: This study investigates the behavior of round jet flow under confinement through experimental and numerical analysis. It shows that the size of the confined space has a significant impact on the flow behavior, leading to a shortened flow distance. The results provide insights into the performance of jet flow confined in a round pipe, offering potential applications in fluid mechanics.
JOURNAL OF APPLIED FLUID MECHANICS
(2021)
Article
Thermodynamics
Ce Liu, Li Jia, Chao Dang, Zhuo Cui, Liaofei Yin
Summary: This study investigated the use of liquid-vapor separation in air-cooled condensers and found that it significantly improved heat transfer, potentially reducing condenser size. Key factors affecting the liquid-vapor separation process included the number of separation devices, wind velocity, and total mass flow rate, with in-tube pressure drop being the dominant parameter affecting efficiency. The liquid-vapor separation condenser design had better thermal-hydraulic performance than a serpentine condenser due to enhanced heat transfer.
JOURNAL OF ENHANCED HEAT TRANSFER
(2021)
Article
Multidisciplinary Sciences
Chao Dang, Yi Ding, Li Jia, Qi Peng
Summary: The dynamic wetting behavior of droplets is crucial for various industrial applications and high technologies. Different methods, including both conventional and innovative approaches, are used to manipulate the wetting characteristics of droplets. Inspired by the phenomenon of droplet floating without gravity, a new manipulation method utilizing a micro-airflow field has been proposed to control the dynamics of droplet wetting.
CHINESE SCIENCE BULLETIN-CHINESE
(2021)