Article
Mechanics
Darren G. Crowdy
Summary: This study presents analytical solutions for longitudinal flow in an annular superhydrophobic pipe with one side being a fully no-slip wall and the other side decorated with longitudinally striped no-shear pattern. It shows how these solutions generalize previous solutions to mixed boundary value problems, providing insights into the hydrodynamic slip enhancement in superhydrophobic surfaces. The study also highlights the importance of maximizing uninterrupted no-shear regions for optimal slip performance in designing slippery pipes.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Tongtong Tao, Zhaochang Wang, Jiawei Ji, Yuhang Guo, Yongqing Zhu, Xidong Hu, Kun Liu, Yunlong Jiao
Summary: In this study, a deflecting air cavity generation strategy utilizing superhydrophobic area occupancy and impact angle control is reported. The influence of these factors on water entry dynamics and drag reduction characteristics of spheres is investigated through experimental and theoretical analysis. The results show that the deflection displacement of a hemispherically coated sphere reaches its maximum when the impact angle is 90 degrees. The SHB region-modulated sphere exhibits different air cavity morphologies and achieves faster movement with reduced drag.
Article
Mechanics
Henry Rodriguez-Broadbent, Darren G. Crowdy
Summary: At high surface Peclet numbers, the presence of surfactants can lead to surface immobilization, but a different mechanism is proposed for longitudinal shear flow along a unidirectional trench at high Marangoni numbers, where the meniscus becomes a constant-shear-stress surface due to contamination by surfactant. Experimental observations support the presence of recirculating interfacial flows on the meniscus. By calculating slip lengths, it is shown that the effective immobilization of the surfaces with vortical flows on the meniscus highlights the caution needed when comparing theory and experiments based on effective slip properties alone.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Behzad Rezaee, Mahmoud Mahlouji Taheri, Hossein Pakzad, Mohammadali Fakhri, Ali Moosavi, Masoud Aryanpour
Summary: In this study, a hierarchical superhydrophobic coating was successfully applied to aluminum surfaces using a cost-effective spraying method. The coated surface exhibited excellent heat transfer enhancement and self-cleaning properties. The results demonstrated that the fabricated surface had high superhydrophobicity with a contact angle of 158 degrees and contact angle hysteresis of less than 5 degrees. It showed improved performance at lower surface temperatures and exhibited good durability, making it suitable for industrial applications.
Article
Mechanics
Roberto M. de la Cruz, Simo A. Makiharju
Summary: The study investigated how water behaves when a jet impacts surfaces with different levels of hydrophobicity, revealing that gravity, surface tension, inertia, and viscosity all play a role in determining the outcome. On hydrophilic surfaces, water spreads uniformly, while on hydrophobic surfaces, two rims enclose a thin laminar film.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Samuel D. Tomlinson, Frederic Gibou, Paolo Luzzatto-Fegiz, Fernando Temprano-Coleto, Oliver. E. E. Jensen, Julien. R. R. Landel
Summary: This study investigates the effect of soluble surfactant on the performance of superhydrophobic surfaces (SHSs) in drag reduction applications. By analyzing the transport of surfactant in a three-dimensional laminar channel flow, a one-dimensional model is derived to predict drag reduction and surfactant distribution. The importance of this study lies in providing insights into the underlying physics of the drag reduction effect through analysis of velocity field and surfactant concentrations.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Darren G. Crowdy
Summary: Explicit formulas are provided for hydrodynamic slip lengths in longitudinal shear flow over a superhydrophobic grating with partially invaded and weakly curved menisci. The axial velocity of flat depinned menisci displaced into cavities is determined analytically to extract the slip length. This solution, combined with an integral identity, determines the first-order correction to slip length when menisci bow weakly into the cavity.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Multidisciplinary
Hamed Esmaeilzadeh, Keqin Zheng, Carol Barry, Joey Mead, Majid Charmchi, Hongwei Sun
Summary: This study evaluated the performance of hydrophobic surfaces under external hydrostatic pressures using an acoustic wave device (QCM), finding that the wetting state of hydrophobic surfaces transitions at a critical hydrostatic pressure and the drag reduction induced by the surfaces decreases with increasing pressure.
Article
Chemistry, Physical
Xue-sen Lv, Yao Qin, Hang Liang, Boxuan Zhao, Yan He, Xuemin Cui
Summary: A composite coating consisting of a zinc coating and superhydrophobic surface was proposed for protecting marine metals, with the innovation of using geopolymer and sand particles to construct a rough micro structure. The designed steel coating demonstrated excellent superhydrophobic performance, drag reduction rate, and corrosion protection ability.
APPLIED SURFACE SCIENCE
(2021)
Article
Mechanics
Muchen Xu, Ning Yu, John Kim, Chang-Jin ''CJ'' Kim
Summary: This study demonstrates that under controlled flow conditions, the reduction in skin-friction drag can be achieved by using specific microtrench SHPo surfaces. The width of the trenches non-dimensionalized to the viscous length scale is found to govern the extent of skin-friction drag reduction.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Chemistry, Physical
Jingying Su, Fenghua Su, Han Yu, Zeqi Lin, Jianfang Sun
Summary: In this study, a superhydrophobic coating with good durability and drag reduction properties was successfully prepared using a simple drop-coating technique after chemical modification and physical mixing. The addition of low surface free energy material FAS-17 and Poly tetra fluoroethylene (PTFE) significantly improved the hydrophobicity of the coating. The coating maintained superhydrophobicity after abrasion and water impact, demonstrating excellent mechanical durability and self-cleaning properties. It also showed potential application in the express sorting industry for drag reduction.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Yatong Wang, Bingzhe Xu, Zhen Chen, Guohao Li, Zhe Li
Summary: A porous superhydrophobic surface with active air plastron can generate a novel bouncing regime in which drops can hover and spread in the air before rebounding. This phenomenon is a result of the balance between inertia and damping force from the air plastron.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Mechanics
Michael D. Mayer, Darren G. Crowdy
Summary: This study investigates the effects of insoluble surfactants on transverse flow over a superhydrophobic surface. Two mechanisms of surface immobilisation are identified: one is the formation of a stagnant cap at higher surface Peclet numbers, and the other is the formation of an immobilised region near the downstream edge of the meniscus. This study enhances understanding of how insoluble surfactants degrade slip over superhydrophobic surfaces.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Samuel D. Tomlinson, Francois J. Peaudecerf, Fernando Temprano-Coleto, Frederic Gibou, Paolo Luzzatto-Fegiz, Oliver E. Jensen, Julien R. Landel
Summary: Superhydrophobic surfaces (SHSs) have the ability to reduce friction drag in turbulent flows. However, the impact of surfactants on the drag-reducing properties of SHSs under turbulent flow conditions has not been thoroughly studied, as it is currently expensive to predict in direct numerical simulations.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2023)
Article
Thermodynamics
Jiansheng Wang, Jianan Ge, Yuntian Fan, Yuguo Fu, Xueling Liu
Summary: In this paper, the flow behavior in a rectangular channel with miniature riblets (MRs) is investigated numerically. The results show that the MRs effectively reduce drag and improve flow stability, but they also lead to a deterioration in heat transfer performance.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Hongxia Zhou, Fayan Zhu, Guojun Ma, Caihong Xue, Yongkang Hu
SURFACE REVIEW AND LETTERS
(2018)
Article
Geochemistry & Geophysics
Zhibo Tong, Guojun Ma, Xiang Zhang, Yongsheng Cai
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Engineering, Biomedical
Yongtao Lu, Yue Liu, Chengwei Wu, Junyan Li
ANNALS OF BIOMEDICAL ENGINEERING
(2018)
Article
Chemistry, Applied
Wei Zhang, Xin Jin, Heng Li, Run-run Zhang, Cheng-wei Wu
CARBOHYDRATE POLYMERS
(2018)
Article
Oncology
Wen-Tong Zhang, Wen-Wen Zhang, Zhen-Yu He, Jia-Yuan Sun, Lei Zhang, Qing Xia, San-Gang Wu
EXPERT REVIEW OF ANTICANCER THERAPY
(2018)
Editorial Material
Oncology
Wei Zhang, Chengwei Wu, S. Ravi P. Silva
EXPERT REVIEW OF ANTICANCER THERAPY
(2018)
Article
Biophysics
Yongtao Lu, Wenying Zhao, Junyan Li, Chengwei Wu
JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY
(2018)
Article
Physics, Applied
S. K. Han, C. W. Wu, Z. Chen
MODERN PHYSICS LETTERS B
(2018)
Article
Physics, Applied
S. K. Han, W. Zhang, G. J. Ma, C. W. Wu, Z. Chen
MODERN PHYSICS LETTERS B
(2018)
Article
Metallurgy & Metallurgical Engineering
Xia Zhou, Li Li, Dong Wen, Xiao-xia Liu, Cheng-wei Wu
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2018)
Article
Chemistry, Multidisciplinary
Xudong Zuo, Chengwei Wu, Wei Zhang, Wei Gao
Article
Multidisciplinary Sciences
Wei Zhang, Li-fu Liu, Yue-jiao Xiong, Yi-fan Liu, Sheng-bo Yu, Cheng-wei Wu, Weihong Guo
SCIENTIFIC REPORTS
(2018)
Article
Materials Science, Multidisciplinary
Jinhui Wang, Xiaoqiang Li, Peipeng Jin, Shangpeng Li, Guojun Ma, Lei Zhao
MATERIALS RESEARCH EXPRESS
(2018)
Article
Materials Science, Multidisciplinary
Chengwei Wu, Chengxiong Wei, Xin Jin, Riaz Akhtar, Wei Zhang
JOURNAL OF MATERIALS SCIENCE
(2019)
Article
Multidisciplinary Sciences
Wei Zhang, Xin Jin, Heng Li, Run-run Zhang, Cheng-wei Wu