Nature Communications
·
2023
·Vol. 14
·期 1
·1-11
·
IF 16.6
Xu Zijie,Cao Leo N. Y.,Li Chengyu,Luo Yingjin,Su Erming,Wang Weizhe,Tang Wei,Yao Zhaohui,Wang Zhong Lin
Real-time monitoring of flow turbulence is very difficult but extremely important in fluid dynamics, which plays an important role in flight safety and control. Turbulence can cause airflow to detach at the end of the wings, potentially resulting in the aerodynamic stall of aircraft and causing flight accidents. Here, we developed a lightweight and conformable system on the wing surface of aircraft for stall sensing. Quantitative data about airflow turbulence and the degree of boundary layer separation are provided in situ using conjunct signals provided by both triboelectric and piezoelectric effects. Thus, the system can visualize and directly measure the airflow detaching process on the airfoil, and senses the degree of airflow separation during and after a stall for large aircraft and unmanned aerial vehicles.
研究领域:
航空工程
·
流体力学
✓ 已验证
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2021
·
IF 4.872
Yinglei Wu,Tao Sun,Zhongyi He,Xiangqiong Zeng,Tianhui Ren,Erik de Vries,Emile van der Heide
Graphene oxide (GO) underwent a single and double-side modification with octadecylamine (ODA) to MGO1 and MGO2 respectively. MGO1 and MGO2 were incorporated into the O/W base emulsion respectively to change the composition of the boundary layer and the oil phase. It was found that the tribological properties of MGO1-emulsion were better than that of MGO2-emulsion. Chemical composition analysis of the worn surfaces suggests that MGO1 nanosheets might adsorb more easily onto the surface and react better with the bearing steel to produce C–N–O–Fe-containing compounds than do MGO2 nanosheets, and that MGO1 nanosheets were more actively involved in the shear process that occurs in the contact area. SEM and nanoindentation indicated that there was a non-uniform softer MGO1-tribofilm on metal substrate.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2024
·
IF 5.8
Zhen-Hua Han,Qi-Bo Wang,Qin-Qin Xu,Xin-Hui Qiu,Tong Cheng,Dong-Sheng Jiao,Jian-Zhong Yin
Sulfuration reactions dominate the synthesis of transition-metal dichalcogenides via chemical vapor deposition. A neglected critical issue is the evolution of crystal domain morphology and growth models caused by boundary layer development. In this study, we propose two growth models within a laminar flow field to investigate the kinetic mechanism of uniformly grown MoS2. We used supercritical fluid pre-deposition to obtain a well-distributed and low-crystallinity Mo precursor on the surface of a substrate to avoid non-stoichiometric supply in sulfuration. The development of the boundary layer was suppressed through mainstream force by adjusting the substrate slope angle. For growth within the underdeveloped laminar boundary layer, monolayer MoS2 with a size of 50 μm uniformly distributed on the full substrate with R = 85% (relative change in boundary layer thickness). Moreover, the growth constrained by surface chemical reactions tended to promote spatially uniform growth. However, within the fully developed laminar flow, the crystal domains preferentially grew vertically, which was attributed to the excessive crystal growth rate (g). Our results provide new insights into the controllable preparation of two-dimensional materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EXPERIMENTAL THERMAL AND FLUID SCIENCE
·
2020
·
IF 3.444
Weidong Shi,Fengyu Li,Qizhao Lin,Guofeng Fang,Liang Chen,Liang Zhang
The effects of nano-alumina additives on the instability of round water jets were experimentally studied. The flow visualization inside and near the exit of two transparent nozzles was obtained by high-speed shadow imaging. A spectrum analysis method was applied to determine the surface wavelengths by performing fast Fourier transform on the image grayscale standard deviation data. According to the flow structure inside the sharp-edged nozzle, an integrated model for wavelength prediction was constructed based on the boundary layer instability theory. The effects of the nanoparticle additives on the jet instability were mainly caused by viscosity enhancement and cavitation promotion. The effects were divided into three categories according to the cavitation state in the nozzle. Firstly, for the no-cavitation flow, the nanoparticles exerted a frequency-reduction effect owing to the viscosity increase. Secondly, for the partial cavitation state, the nanoparticles had an increasing-frequency effect owing to the internal cavitation enhancement. Thirdly, for supercavitation or high-speed flow, the dominant frequency no longer changed, whereas the nanoparticles increased the jet instability owing to the enhancements in the external cavitation and aerodynamic force.
研究领域:
流体力学
·
纳米技术
·
实验物理学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2023
·
IF 7.4
Qi Wang,Zhe Ding,Gary Wong,Jia Zhou,Antoine Riaud
Acoustic mixing of droplets is a promising way to implement biosensors that combine high speed and minimal reagent consumption. To date, this type of droplet mixing is driven by a volume force resulting from the absorption of high-frequency acoustic waves in the bulk of the fluid. Here, we show that the speed of these sensors is limited by the slow advection of analyte to the sensor surface due to the formation of a hydrodynamic boundary layer. We eliminate this hydrodynamic boundary layer by using much lower ultrasonic frequencies to excite the droplet, which drives a Rayleigh streaming that behaves essentially like a slip velocity. At equal average flow velocity in the droplet, both experiment and three-dimensional simulations show that this provides a three-fold speedup compared to Eckart streaming. Experimentally, we further shorten a SARS-CoV-2 antibody immunoassay from 20 min to 40 s taking advantage of Rayleigh acoustic streaming.
研究领域:
生物传感器
·
声流体学
·
分析化学
·
微流控
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IEEE TRANSACTIONS ON PLASMA SCIENCE
·
2014
·Vol. 42
·期 2
·358-375
·
IF 0.95
Emmanouil D. Fylladitakis,Michael P. Theodoridis,Antonios X. Moronis
Corona discharge refers to the phenomenon when the electric field near a conductor is strong enough to ionize the dielectric surrounding it but not strong enough to cause an electrical breakdown or arcing between conductors or other components. This phenomenon is unwanted and dangerous in high-voltage systems; however, a controlled corona discharge may be used to ionize a fluid and induce motion by directly converting the electrical energy into kinetic energy. Phenomena that involve the direct conversion of electrical energy into kinetic energy are known as electrohydrodynamic (EHD) and have a variety of possible applications today. This paper contains a literature review of the research regarding the EHD effects associated with corona discharges, from the first observation of the phenomenon to the most recent advancements on its mathematical modeling, as well as the advancements on specific applications, such as thrust, heat transfer improvement, boundary layer enhancement, drying, fluid pumping, and cooling.
研究领域:
物理电子学
·
流体力学
·
热力学
·
应用数学
·
电气工程
·
材料科学
✓ 已验证
DOI
高影响因子
FIBERS AND POLYMERS
·
2021
·Vol. 22
·期 5
·1482-1489
·
IF 2.153
Wang Wuchao,Zhou Qi,Long Haofan,Zhang Yanyun,Rather Luqman Jameel,Li Qing
Research into the industrial practice of ultrasonic aqueous textile cleaning is still underway despite success in the technology being used in other cleaning industry. This study uses ultrasonic frequencies of 40 kHz, 60 kHz and 80 kHz to examine frequency dependence of ultrasonic textile laundry. Results showed that fabric washing efficiency is not proportional to the ultrasonic frequency. Ultrasonics at a lower (40 kHz) or higher frequency (80 kHz) showed a better washing efficiency than that at 60 kHz, especially for the removal of stubborn stain and for natural textile materials such as wool and silk. The reason lies in the mechanism of cavitation implosion, micro-streaming induced changes in surface boundary layer, as well as the intricate micro-structure of the fibre surface. These were analyzed and discussed in detail in the paper.
研究领域:
材料科学
·
纺织工程
·
声学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Parvaiz Ahmad Naik,N. Indumathi,B. Ganga,S. Charles,A. K. Abdul Hakeem,Zahoor Iqbal,ElSayed Tag-ElDin,Jian Zu
The topic of two-dimensional steady laminar MHD boundary layer flow across a wedge with non-Newtonian hybrid nanoliquid (CuO-TiO2/C2H6O2) with viscous dissipation and radiation is taken into consideration. The controlling partial differential equations have been converted to non-linear higher-order ordinary differential equations using the appropriate similarity transformations. It is demonstrated that a number of thermo-physical characteristics govern the transmuted model. The issue is then mathematically resolved. When the method’s accuracy is compared to results that have already been published, an excellent agreement is found. While the thermal distribution increases with an increase in Eckert number, radiation and porosity parameters, the velocity distribution decreases as porosity increases.
研究领域:
流体力学
·
传热传质
·
纳米流体
·
磁流体动力学
·
多孔介质
·
非牛顿流体
·
能源工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Li Zhang,Wanlin Wang,Lei Zhang,Jie Zeng,Xu Gao
The dissolution mechanism of Al 2 O 3 inclusions in molten slags was explored by in-situ single hot thermocouple technique combined with X-ray photoelectron spectroscopy. Result shows that it takes 2940 s to completely dissolve Al 2 O 3 inclusions in the molten F-bearing mold flux, which is mainly controlled by boundary layer diffusion. Because the connected [AlO 6 ] octahedra in the Al 2 O 3 inclusion is gradually destroyed by the O 2− ions in the melt. By comparison, the CaO–SiO 2 –B 2 O 3 based F-free mold flux only takes 840 s to completely dissolve Al 2 O 3 inclusions. Because the [AlO 6 ] octahedra is destroyed and further transformed to [AlO 4 ] tetrahedra and produce O 2− ions, which greatly facilitates the dissociation of the Al 2 O 3 particle. However, the formed [AlO 4 ] tetrahedra will promote the precipitation of the dense 2CaO·SiO 2 ·Al 2 O 3 crystals, which tightly encases the Al 2 O 3 particle and causes significant drop in the dissolution rate. Thus, the dissolution rate is controlled by chemical reaction and then by boundary layer diffusion.
研究领域:
冶金学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Wei Wang,Liu-Liu Shen,Peiran Wu,Hui Yu,Jiansong Wang,Yipu Xu,Xiangzun Dong,Xuanxuan Cui,Gui-Rong Zhang,Donghai Mei
Capillary microfluidics on porous substrates emerges as an innovative platform for constructing miniaturized electronics. However, maintaining a steady flow within microfluidics remains challenging, thus limiting their practical applications. Inspired by plant transpiration, this work presents a novel wood-based microfluidic Al-air battery (μAAB) configuration driven by a photothermal evaporator (biomimetic “leaf”). Except for the Al anode, the μAAB features an all-wood design, utilizing the well-aligned microchannels of the natural wood for electrolyte transportation, partially charred wood as photothermal evaporator for flow regulating, and wood-derived self-standing carbon cathode for the oxygen reduction reaction. These components are assembled through mortise-and-tenon joints, and the resulting μAAB exhibits a remarkable peak power density of 230 mW cm −3 . The superior performance stems from the boosted mass transfer, maximized electrochemical interface and minimized depletion boundary layer provided by the 3D channeled structure of the wood-derived cathode. A steady discharge for over 11 h (200 mA cm −3 ) is obtained via the continuous electrolyte flow which is facilitated by the photothermal evaporator in the μAAB. This work not only presents a novel concept for miniaturized microfluidic power sources but also highlights the potential of 3D wood-based microfluidics combined with solar energy utilization.
研究领域:
材料科学
·
能源技术
·
微流控
·
可持续能源
·
仿生学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）