Article
Engineering, Mechanical
Jingjing Liu, Yong Wang, Zhicheng Yuan
Summary: Pattern texturing has been proven to enhance water repellency on hydrophobic surfaces. In this study, the effect of pattern profile on dynamic wetting state is investigated numerically. Trapezoid topography is found to effectively prevent wetting, and masking groove side-walls with superhydrophobic patterns can result in a stable dry surface.
JOURNAL OF FLUIDS AND STRUCTURES
(2023)
Article
Chemistry, Physical
Fenhong Song, Jiayu Xue, Bing Ma, Jing Fan, Yuchen Wang, Yuhui Jiang
Summary: Molecular dynamic simulation was used to investigate the wetting and electro-wetting behavior of nanodroplets of ionic liquid on a silicon solid substrate, as well as the influence of solid wettability and temperature on the wetting phenomenon. The results indicate that the equilibrium contact angle decreases with increasing solid wettability and temperature. When the nanodroplet wets a lyophilic surface, the effect of temperature is more pronounced. The droplet exhibits asymmetric electro-wetting on the lyophobic surface under the applied electric field, and this asymmetry diminishes with increasing energy parameter. The redistribution of cationic and anionic particles on the first wetting layer is found to be the main factor influencing the wetting behaviors.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Mechanics
Zhicheng Yuan, Mitsuhiro Matsumoto, Ryoichi Kurose
Summary: This study proposes a textured surface with primary and secondary structures to enhance hydrophobicity and stabilize the non-wetting state. The research shows that decorating the surface with hierarchical structures improves both the surface hydrophobicity and the non-wetting stability.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Mechanics
Prakasha Chandra Sahoo, Jnana Ranjan Senapati, Basanta Kumar Rana
Summary: This paper numerically investigates the dynamic characteristics of a water droplet impact on a thin vertical solid cylinder and predicts complex hydrodynamic behaviors. The study reveals that the maximum deformation factor is influenced by the contact angle, cylinder-to-droplet diameter ratio, Weber number, and Ohnesorge number. An analytical model and a correlation are developed to explain and predict the maximum deformation factor, which show good agreement with the numerical results.
Article
Mechanics
Wen Li, Jingxin Wang, Chuling Zhu, Linlin Tian, Ning Zhao
Summary: The impact of microscale water droplets on a solid superhydrophobic surface was numerically investigated. The study found that the maximum spreading parameter increases with ambient temperature for droplets impacting with constant velocity and diameter. As Weber and Reynolds numbers increase, the impact transitions into a doughnut-breakup regime, forming a toroidal shape and central cavity.
Article
Chemistry, Multidisciplinary
Han Ge, Kaichuang Wang, Jiawang Chen, Ronghua Zhu, Marisa Lazarus, Dayun Yan
Summary: This paper numerically studies the air entrapment of a micron-sized molten nickel droplet impacting on a stainless-steel substrate. The results show that, besides the air entrapped during the high-speed impacting, bubbles may also be entrapped due to the fallback of the pointed-out finger on the edge during the spreading process. The number and size of the entrapped bubbles are related to the solidification rate and spreading rate.
APPLIED SCIENCES-BASEL
(2022)
Article
Thermodynamics
Changwei Xu, Wen Nie, Huitian Peng, Shaobo Zhang, Fei Liu, Shixing Yi, Xingpeng Cha, Felicie Ilele Mwabaima
Summary: The dust particles generated during coal mining and processing are usually removed by spray dust reduction. The contact wetting and wrapping process of dust particles by droplets were analyzed under different particle size ratios and initial droplet velocities. The results showed that the larger the particle size ratio, the more variation in the spreading coefficient. When the particle size ratio was more than 2, the droplets could completely wrap the coal dust particles. The optimized parameters achieved an average settling efficiency of 86.2% for respirable dust in the mine return air duct.
Article
Thermodynamics
Yukai Lin, Fuqiang Chu, Xiaomin Wu
Summary: This study uses moving-mesh numerical simulation to investigate the evaporation of droplets at different wetting modes and finds that the simulation results of mixed mode evaporation agree well with experiments. The effect of wetting modes on the variation of multiple physical fields is elucidated, and the study has promising applications in industrial and technological fields such as thermal management, droplet microfluidics, and medical treatment.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Physical
Hang Dong, Yu Zhou, Chao Zheng, Jianping Zhou
Summary: Amphiphobic surface can repel both water and oil, and the surface characteristic energy and surface charge of the surface have significant effects on the wetting behaviors of water and oil droplets, with larger effects on oil droplets. Increasing the characteristic energy and charge will decrease the contact angles of water and oil droplets on the amphiphobic surface.
APPLIED SURFACE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Wanghuai Xu, Yuankai Jin, Wanbo Li, Yuxin Song, Shouwei Gao, Baoping Zhang, Lili Wang, Miaomiao Cui, Xiantong Yan, Zuankai Wang
Summary: Liquid manipulation is important, and electrowetting on dielectric (EWOD) is a commonly used method. However, EWOD requires complex circuit control. Here, we develop an unexplored triboelectric wetting (TEW) phenomenon that directly uses triboelectric charges for precise water droplet control, eliminating the need for circuit control.
Article
Engineering, Chemical
Qingwen Dai, Chuchen Yue, Wei Huang, Xiaolei Wang
Summary: The impact dynamics of oil droplets on curved surfaces are studied in this work. The effects of curvature, surface roughness, rotating speed, and wetting conditions on the impact dynamics are investigated. The deformation of droplets on rotating cylinders is found to be more significant than on static ones. An interesting bouncing phenomenon is observed on rotating, pre-wetted, and curved surfaces, and the bouncing dynamics under different conditions are highlighted. Numerical simulation shows that the sunken liquid film on the cylinder surface generates a liquid camber and seals compressed air, providing a cushion effect for droplets bouncing. Critical conditions are given to identify the velocity thresholds for droplets bouncing and depositing. This work provides a fundamental understanding of droplets impact dynamics on curved surfaces and assists in the design of applications in modern industry, such as mist lubrication systems.
CHEMICAL ENGINEERING SCIENCE
(2023)
Review
Chemistry, Physical
Qiaoli Lin, Kaibin Xie, Ran Sui, Dekui Mu, Rui Cao, Jinghuan Chang, Feng Qiu
Summary: This study reviews the current status of wetting dynamic models, highlighting the challenges in understanding high-temperature interface kinetic processes for composite materials. Common analysis errors in metal-ceramic and metal-metal systems are identified in describing wetting dynamics.
ADVANCES IN COLLOID AND INTERFACE SCIENCE
(2022)
Article
Thermodynamics
Baris Burak Kanbur, Marcus Zhao Hui Lee, Fei Duan
Summary: This study investigates the transition of high-speed and high-frequency ethanol droplet train impingement on the glass substrate, analyzing the changes in surface temperature along 50 milliseconds. The spreading diameter trends depend on the thermal balance between the supplied liquid ethanol and the ethanol consumption from the glass surface, with the diameter increasing with increments in the Weber number while decreasing with the rise of the glass surface temperature. The observation of boiling, transition, and post-transition regimes provides insight into the process of droplet impact on the glass surface.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Environmental
Zhishan Yuan, Cheng Zhang, Chujin Qin, Dongke Sun, Mingting Qiu, Haiyu Wang, Chengyong Wang
Summary: The study achieved high-speed gravity-driven oil-water separation by pre-wetting river sand, sea sand, and desert sand. The relationship between the porosity of different sand types and the water phase separation rate was obtained using the LBM Shan-Chen model and micro-CT characterization. Other factors affecting the rate of oil-water separation were also investigated.
JOURNAL OF WATER PROCESS ENGINEERING
(2022)
Article
Thermodynamics
Lihui Liu, Yichi Zhang, Guobiao Cai, Peichun Amy Tsai
Summary: The impact of droplets on heated surfaces is crucial in various applications. Temperature variations during impact are significantly influenced by dynamics, with different behaviors observed at different Weber numbers and initial surface temperatures. Temperature changes in both droplets and surfaces are related to the energy conservation principle.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Laxman K. Malla, Rajneesh Bhardwaj, Adrian Neild
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2020)
Article
Chemistry, Multidisciplinary
Sagar N. Agnihotri, Mohammad Reza Raveshi, Rajneesh Bhardwaj, Adrian Neild
Article
Engineering, Manufacturing
Ankit Kumar, Rajneesh Bhardwaj, Suhas S. Joshi
MACHINING SCIENCE AND TECHNOLOGY
(2020)
Article
Mechanics
Manish Kumar, Rajneesh Bhardwaj, Kirti Chandra Sahu
Article
Multidisciplinary Sciences
Manish Kumar, Rajneesh Bhardwaj
SCIENTIFIC REPORTS
(2020)
Article
Engineering, Mechanical
Rahul Mishra, Atul Soti, Rajneesh Bhardwaj, Salil S. Kulkarni, Mark C. Thompson
JOURNAL OF FLUIDS AND STRUCTURES
(2020)
Article
Chemistry, Multidisciplinary
Manish Kumar, Rajneesh Bhardwaj, Kirti Chandra Sahu
Article
Chemistry, Multidisciplinary
Sanghamitro Chatterjee, Manish Kumar, Janani Srree Murallidharan, Rajneesh Bhardwaj
Article
Engineering, Mechanical
Rahul Mishra, Rajneesh Bhardwaj, Salil S. Kulkarni, Mark C. Thompson
Summary: This study investigates the effect of structural nonlinearity on the vortex-induced vibration of a rigid circular cylinder at a fixed mass ratio of m* = 2.546 and Re = 150. By changing the damping ratio and nonlinearity strength, the response of the cylinder to VIV is examined. Increasing system nonlinearity leads to richer spectral content in displacement and force signals, indicating a potential benefit for energy extraction applications.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Mechanics
Sanghamitro Chatterjee, Janani Srree Murallidharan, Amit Agrawal, Rajneesh Bhardwaj
Summary: The study found that the survival time of coronavirus on porous surfaces is shorter than that on impermeable surfaces due to the changes in the evaporation mechanism and mass loss of droplets in porous materials. Capillary imbibition process and faster film evaporation on porous surfaces play a key role in the faster decay of the virus.
Article
Multidisciplinary Sciences
Javed Shaikh, Nagesh D. Patil, Atul Sharma, Rajneesh Bhardwaj
Summary: The study focuses on the partial/complete coalescence dynamics of a droplet surrounded by air over a horizontal pool of the same liquid. Both experimental and numerical studies were carried out for droplets of constant diameter in isopropanol and glycerol. The numerical study, particularly on isopropanol droplets, investigated the influence of droplet diameter and surface tension coefficient on coalescence dynamics. The study presented a flow and vorticity dynamics-based quantitative evidence of the coalescence mechanism, identified critical values for transition from partial to full coalescence, and demonstrated excellent agreement with existing literature correlations for transition boundaries under varying droplet parameters.
SN APPLIED SCIENCES
(2021)
Article
Thermodynamics
Hemanshul Garg, Atul Kumar Soti, Rajneesh Bhardwaj
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2020)
Article
Materials Science, Multidisciplinary
Ankit Kumar, Rajneesh Bhardwaj, Suhas S. Joshi
ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES
(2020)
Article
Mechanics
Rajneesh Bhardwaj, Amit Agrawal
Article
Multidisciplinary Sciences
Anup Kundu, Atul K. Soti, Hemanshul Garg, Rajneesh Bhardwaj, Mark C. Thompson
SN APPLIED SCIENCES
(2020)
Article
Thermodynamics
Navid Freidoonimehr, Azadeh Jafari, Maziar Arjomandi
Summary: In this study, a high-fidelity flow visualisation technique is used to investigate the resemblance between a turbulent boundary layer generated by different tripping devices in a lab environment and a naturally developed canonical turbulent boundary layer. The study finds that the blockage created by trips is the main factor affecting the turbulence statistics at a certain downstream distance.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
Yuning Wang, Alberto Solera-Rico, Carlos Sanmiguel Vila, Ricardo Vinuesa
Summary: This study proposes a method that combines 6-VAEs for modal decomposition and transformer neural networks for temporal-dynamics prediction in the latent space to develop reduced-order models (ROMs) for turbulent flows. The method achieves high reconstruction accuracy and accurate prediction of temporal dynamics.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
L. Laguarda, S. Hickel, F. F. J. Schrijer, B. W. van Oudheusden
Summary: Wall-resolved large-eddy simulations were used to investigate the Reynolds number effects in supersonic turbulent boundary layers at Mach 2.0. The study covered a wide range of friction Reynolds numbers and identified trends in various statistics and scaling laws. The size and topology of turbulent structures in the boundary layer were examined, with a focus on the outer-layer motions at high Reynolds numbers. The study also assessed the influence of outer-layer structures on near-wall turbulence and the sensitivity of uniform momentum regions to compressibility.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
A. Doehring, T. Kaller, S. J. Schmidt, N. A. Adams
Summary: In this study, well-resolved large-eddy simulations were used to investigate turbulent duct flows with a square cross section. The influence of a modified wall shear stress on the secondary flow was analyzed by artificially modifying the wall shear stress at one of the four walls. The results showed that the modification led to an asymmetrical distribution of the secondary flow source terms, affecting the momentum distribution. Furthermore, the anisotropy of the Reynolds stress tensor, which induces the secondary flow vortices, was significantly affected by the wall shear stress modulation.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
