1
|
Liu X, Liu L, Zhang W, Xie J, Duan R. Flow and Heat-Transfer Characteristics of Droplet Impingement on Hydrophilic Wires. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:15597-15609. [PMID: 37877142 DOI: 10.1021/acs.langmuir.3c01904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
It is a common phenomenon that droplets collide with wires in industrial production, and their flow and heat-transfer behavior significantly impact the production efficiency. This article presents an experimental and numerical study on the impact of pure water droplets on hydrophilic stainless-steel wires. The dynamic behavior and solid-liquid heat-transfer law of droplet impacting the wire are emphatically analyzed. The impact position of the droplets has a significant effect on their morphology. Under the condition of low Weber number (We), eccentric impacts tend to cause droplets to separate from the wire. Additionally, both We and wire/droplet size ratio have noticeable effects on the droplet morphology. The smaller the We, the larger the wire/droplet size ratio, and the easier it is for droplets to be captured by wires. Conversely, as We increases and the wire-to-droplet size ratio decreases, some droplets become detached from the wire, primarily exhibiting a single-film falling mode. Furthermore, the impact morphology of droplets is influenced by the Ohnesorge number (Oh). The higher the Oh, the more inclined the droplet to develop a double-film falling mode. There is obvious field synergy in the process of droplet impacting on wire. The maximum heat flux is located at the three-phase contact line, while the minimum heat flux is observed at the bubble interface. The impact position of droplets influences the temperature distribution, although its impact on the magnitude of temperature variation is minimal.
Collapse
Affiliation(s)
- Xuanchen Liu
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Liansheng Liu
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Thermal Science and Energy Clean Utilization, Tianjin 300401, China
| | - Wenrui Zhang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Jun Xie
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
| | - Runze Duan
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
- Hebei Key Laboratory of Thermal Science and Energy Clean Utilization, Tianjin 300401, China
| |
Collapse
|
2
|
He X, Liu X, Tang J, Dong H, Sugawara Y, Li YJ, Ma Z, Liu J. Effect of Preparation Processes on Structural Thermal Stability and Collision Energy Dissipation of Common Antirelaxation Coatings on Quartz Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:12740-12753. [PMID: 37651224 DOI: 10.1021/acs.langmuir.3c01480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Paraffin and octadecyltrichlorosilane (OTS) coatings can alleviate collisions between alkali-metal atoms and cell walls and then prolong the atomic spin-polarization lifetime. The surface structure and collision effects of these antirelaxation coatings, as well as the methods to avoid antirelaxation invalidity, have been the focus of researchers. This study investigated the thermolability of coating surface structure and the collision interactions between alkali metal atoms and coatings, considering the influence of various coating preparation factors, where this collision interaction is indirectly analyzed by measuring the collision energy dissipation between an atomic force microscopy (AFM) probe and the atoms on the coating surface. We found that appropriate evaporation time, carbochain length, and postannealing process can enhance the thermostability of the paraffin coating and eliminate its morphological defects. Furthermore, the OTS/water concentration, the soaking time, and the type of solvent have different levels of influence on the cluster formation and the thermostability of the OTS coatings. Moreover, the antirelaxation performance of coatings has been shown to be characterized by counting the energy dissipated when the AFM probe collides with the antirelaxation coating, replacing the conventional light-atom interaction- based method for measuring the relaxation characteristics, but requiring specific coating preparation factors to be maintained.
Collapse
Affiliation(s)
- Xinxin He
- School of Instrument and Electronics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
- National Key Laboratory for Dynamic Measurement Technology, North University of China, Taiyuan 030051, People's Republic of China
| | - Xiaoya Liu
- School of Instrument and Electronics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
- National Key Laboratory for Dynamic Measurement Technology, North University of China, Taiyuan 030051, People's Republic of China
| | - Jun Tang
- National Key Laboratory for Dynamic Measurement Technology, North University of China, Taiyuan 030051, People's Republic of China
- School of Semiconductor and Physics, North University of China, Taiyuan 030051, People's Republic of China
| | - Haifeng Dong
- School of Instrumentation Science and Optoelectronics Engineering, Beihang University, Beijing 100191, People's Republic of China
| | - Yasuhiro Sugawara
- Department of Applied Physics, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871, Japan
| | - Yan Jun Li
- School of Instrument and Electronics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
- Department of Applied Physics, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871, Japan
| | - Zongmin Ma
- National Key Laboratory for Dynamic Measurement Technology, North University of China, Taiyuan 030051, People's Republic of China
- School of Semiconductor and Physics, North University of China, Taiyuan 030051, People's Republic of China
| | - Jun Liu
- School of Instrument and Electronics, North University of China, Taiyuan, Shanxi 030051, People's Republic of China
- National Key Laboratory for Dynamic Measurement Technology, North University of China, Taiyuan 030051, People's Republic of China
| |
Collapse
|
3
|
Han F, Zhao Y, Liu M, Hu F, Peng Y, Ma L. Effect of Sodium Carboxymethyl Cellulose on the Dynamic Wetting Characteristics of the Dust Suppression Droplet Impacting the Coal Surface. ACS OMEGA 2023; 8:18414-18424. [PMID: 37273585 PMCID: PMC10233664 DOI: 10.1021/acsomega.2c07783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 05/04/2023] [Indexed: 06/06/2023]
Abstract
The dynamic wetting behavior of droplets impacting the coal surface directly affects the efficient application of water-based dust suppression materials in coal-related industrial production. In this paper, ultrapure water, Tween-80, and sodium carboxymethyl cellulose are taken as the research objects. Using high-speed photography technology, the spreading, oscillation process, and splash morphology of many kinds of droplets during impacting the coal surface are captured. The effects of viscosity, surface tension, and impact velocity on dynamic wetting characteristics were studied. The results show that with the decrease of surface tension, the retraction and oscillation of droplets are significantly reduced. For the same kind of droplets, the greater the impact velocity, the faster the droplet spread, and the dimensionless maximum spreading coefficient (βmax) and dimensionless steady-state spreading coefficient (βe) of droplets are bigger. With the increase of velocity, the time for different kinds of droplets to reach the βmax increases. At the same impact velocity, βmax and βe of droplets (0.2% Tween-80 + 0.1% sodium carboxymethyl cellulose) are the largest, indicating that adding a small amount of sodium carboxymethyl cellulose can promote droplet spreading. With the increase of sodium carboxymethyl cellulose content, βmax and βe decreased gradually. The results have a great significance to the research, development, and scientific utilization of water-soluble polymer dust inhibitors.
Collapse
Affiliation(s)
- Fangwei Han
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
- Key
Laboratory of Mine Thermodynamic Disasters and Control, Ministry of
Education, Liaoning Technical University, Huludao 125105, Liaoning Province, China
| | - Yue Zhao
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
| | - Mei Liu
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
| | - Fuhong Hu
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
| | - Yingying Peng
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
| | - Liang Ma
- College
of Safety Science and Engineering, Liaoning
Technical University, Huludao 125105, Liaoning Province, China
| |
Collapse
|
4
|
Jaiswal AK, Khandekar S. Role of offset during drop-on-drop impact dynamics on a superhydrophobic substrate. RESULTS IN SURFACES AND INTERFACES 2023. [DOI: 10.1016/j.rsurfi.2023.100102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
|
5
|
Wang Y, Zhao Y, Sun L, Mehrizi AA, Lin S, Guo J, Chen L. Successive Rebounds of Impinging Water Droplets on Superhydrophobic Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3860-3867. [PMID: 35293214 DOI: 10.1021/acs.langmuir.2c00114] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
When a water droplet strikes a superhydrophobic surface, there may be several to a few tens of rebounds before it comes to rest. Although this intriguing multiphase flow phenomenon has received a great deal of attention from interfacial scientists and engineers, the underlying dynamics have not yet been completely resolved. In this paper, we report on an experimental investigation into the bouncing behavior of water droplets impinging on macroscopically flat superhydrophobic surfaces. We show that the restitution coefficient, which quantifies the energy consumed during impact and rebound, exhibits a nonmonotonic dependence on the Weber number. It is the droplet-surface friction that restricts the rebound height of the impinging droplet, so its restitution coefficient increases with the Weber number when the impact velocity is below a critical value. Above this value, the viscous friction within a thin liquid layer close to the superhydrophobic surface becomes dominant, and thus, the restitution coefficient decreases sharply. On the basis of energy analyses, semiempirical formulas are proposed to describe the restitution coefficient, and these can be employed to predict the number of successive rebounds of impinging droplets on superhydrophobic surfaces.
Collapse
Affiliation(s)
- Yile Wang
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
| | - Yage Zhao
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
| | - Lijie Sun
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
| | - Abbasali Abouei Mehrizi
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
| | - Shiji Lin
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, People's Republic of China
| | - Jianwei Guo
- School of Mechanics and Aerospace Engineering, Southwest Jiaotong University, Chengdu 610031, People's Republic of China
| | - Longquan Chen
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, People's Republic of China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, People's Republic of China
| |
Collapse
|
6
|
Yilbas BS, Abubakar A, Yakubu M, Al-Qahtani H, Al-Sharafi A. Nanowall Textured Hydrophobic Surfaces and Liquid Droplet Impact. MATERIALS (BASEL, SWITZERLAND) 2022; 15:1645. [PMID: 35268876 PMCID: PMC8911166 DOI: 10.3390/ma15051645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 11/17/2022]
Abstract
Water droplet impact on nanowires/nanowalls' textured hydrophobic silicon surfaces was examined by assessing the influence of texture on the droplet impact dynamics. Silicon wafer surfaces were treated, resulting in closely packed nanowire/nanowall textures with an average spacing and height of 130 nm and 10.45 μm, respectively. The top surfaces of the nanowires/nanowalls were hydrophobized through the deposition of functionalized silica nanoparticles, resulting in a droplet contact angle of 158° ± 2° with a hysteresis of 4° ± 1°. A high-speed camera was utilized to monitor the impacting droplets on hydrophobized nanowires/nanowalls' textured surfaces. The nanowires/nanowalls texturing of the surface enhances the pinning of the droplet on the impacted surface and lowers the droplet spreading. The maximum spreading diameter of the impacting droplet on the hydrophobized nanowires/nanowalls surfaces becomes smaller than that of the hydrophobized as-received silicon, hydrophobized graphite, micro-grooved, and nano-springs surfaces. Penetration of the impacted droplet fluid into the nanowall-cell structures increases trapped air pressure in the cells, acting as an air cushion at the interface of the droplet fluid and nanowalls' top surface. This lowers the droplet pinning and reduces the work of droplet volume deformation while enhancing the droplet rebound height.
Collapse
Affiliation(s)
- Bekir Sami Yilbas
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; (A.A.); (M.Y.); (H.A.-Q.); (A.A.-S.)
- IRC for Renewable Energy and Power, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- K.A. CARE Energy Research and Innovation Center, Dhahran 31261, Saudi Arabia
- Engineering Faculty, Turkish Japanese University, Istanbul 34906, Turkey
| | - Abba Abubakar
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; (A.A.); (M.Y.); (H.A.-Q.); (A.A.-S.)
| | - Mubarak Yakubu
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; (A.A.); (M.Y.); (H.A.-Q.); (A.A.-S.)
| | - Hussain Al-Qahtani
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; (A.A.); (M.Y.); (H.A.-Q.); (A.A.-S.)
- IRC for Renewable Energy and Power, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Abdullah Al-Sharafi
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia; (A.A.); (M.Y.); (H.A.-Q.); (A.A.-S.)
- IRC for Renewable Energy and Power, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- K.A. CARE Energy Research and Innovation Center, Dhahran 31261, Saudi Arabia
| |
Collapse
|