LANGMUIR
·
2020
·
IF 3.557
Yunrui Han,Shipeng Wang,Lin Han,Limin He,Xiaoming Luo
In this aticle, the continuous movement patterns and characteristic parameters of oil droplets on surfaces with different wettability immersed in a laminar flow field were observed, and the change rules of the geometric parameters of oil droplets under different experimental conditions were obtained. Then, the factors influencing the continuous moving behaviors of the oil droplets were analyzed, and the continuous movement velocity of the oil droplets under different experimental conditions was demonstrated. On this basis, the change law of the continuous movement velocity of oil droplets with the flow velocity was discussed. In addition, the coupling effect of the oil drops’ height, surface properties, and water flow velocity on the continuous movement of oil droplets was studied, and the critical conditions for the continuous movement were obtained. According to the critical conditions, the mathematical model which described the law of continuous motion of the oil droplets adhered on surfaces with different wettability in the laminar flow field was established. The quantitative relationships among the average continuous moving velocity of oil droplets, physical properties, geometric parameters, water flow velocity, and surface wettability were obtained, which defined the necessary conditions for the uniform and accelerated movement of oil droplets, providing an important basis for choices of suitable surface wettability and flow field conditions in practical engineering applications.
研究领域:
物理学
·
工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2021
·
IF 5.584
Shengna Liu,Liancun Zheng
The classical constitutive equations for heat transfer of non-Newtonian fluids in shear flow fields neglect viscous dissipation and the field synergistic properties of rheology and heat transfer. In this paper, a novel constitutive Eq. (6) for rheological synergy thermal conductivity was derived by considering viscous dissipation. Based on this, we established an experimental platform to investigate the heat transfer properties of HEC-based silicon dioxide nanofluids (different nanoparticle sizes and volume fractions) in shear flow field for two cases: neglecting viscous dissipation and considering viscous dissipation. The results show that viscous dissipation have very important effects on heat transfer behavior at different shear rates and rheological properties. The contribution of viscous dissipation to the thermal conductivity increases with shear rate and particle volume fraction, but decreases with temperature. Among all the measured results, the maximum contribution of viscous dissipation to the thermal conductivity reached 19.86%. This confirms that the viscous dissipation is not negligible and the field synergy between rheology and heat transfer of non-Newtonian fluids must be considered in the shear flow fields.
研究领域:
热力学
·
流体力学
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2023
·
IF 3.5
Peiyi Yan,Ying Zhang,Shili Zheng
Hydrolysis of TiCl 4 solution is capable of preparing microscale TiO 2 particles. This research studied the synthesis of microscale spherical TiO 2 powders and the hydrolysis kinetics. The effects of the flow field generated by different agitators and baffles in the crystallizer, the initial free acid concentration, the initial equivalent TiO 2 concentration, and the temperature on the hydrolysis progress and powder morphology were systematically studied. The results show that the flow field in a crystallizer can significantly affect the morphology and particle size of the powders, and the axial flow can improve the sphericity of the powders. The increased free HCl and equivalent TiO 2 concentrations in the pregnant solution inhibit the forward hydrolysis reaction, prolong the time to reach equilibrium, and reduce the yield. An appropriate temperature matching the compositions of the pregnant solution is crucial for the powder morphology and size. Powders with sizes ranging from around 5 μm–40 μm can be tuned under controlled flow field, solution compositions, and temperature conditions. In addition, the Cheng and Wunderlich modified Avrami equation was used for the crystallization kinetic modeling. The effects of the free HCl concentration, equivalent TiO 2 concentration, and hydrolysis temperature are reflected in the reaction rate constant and active nuclei reduction index. Increasing the free HCl and equivalent TiO 2 concentrations will reduce the reaction rate constant and accelerate the deactivation of the active nuclei, thus increasing the final powder size, while increasing the temperature will lead to the opposite results.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Manufacturing Processes
·
2024
·
IF 6.1
Qing Wang,Pengfei Su,Zhenyu Lei,Mingxiang Chen,Xiaobing Luo
The copper pattern electroplating rate significantly impacts electronic packaging substrate preparation efficiency. The direct current (DC) electroplating technique has great potential in economy and convenience but faces challenges in improving the electroplating rate and coating properties, thus making electroplating additives the most critical parameters for controlling the electroplating process and coating properties. Convection and cathodic polarization are two essential parameters influencing the additives' interactions, but the electrolyte flow field distribution is complicated by the changed pattern size, and most electrolyte formulas cannot withstand such strong cathodic polarization. Therefore, we presented a novel electrolyte formula for ultra-high-rate DC copper pattern electroplating and employed three-dimensional flow field simulation to investigate the flow field distribution throughout the patterns. An ultra-high current density of 8 A/dm 2 was applied, ensuring a stable electroplating process. The pattern size-stimulated electrolyte flow rate trend was discovered by simulations. The mechanism of simultaneously achieving ultra-high-rate electroplating and coating property improvement was thoroughly investigated. An ultra-high rate of 150 μm/h and the dense, uniform copper pattern coating were achieved synchronously with weak convection and strong cathodic polarization. Utilizing the ultra-high-rate copper electroplating method offers a viable approach to expedite the production of electronic packaging substrate with enhanced efficiency.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2019
·
IF 3.683
Yunrui Han,Shipeng Wang,Rifeng Zhou,Limin He,Xiaoming Luo
In this article, the rising trajectories of oil droplets near the substrates of small channels in the laminar flow field were observed using a high-speed camera. Chemical modifications were made on the surfaces of the brass sheets to change the surface properties, and the controllable regulation of the superoleophilic–superoleophobic wettability gradient was achieved. The adhesion behaviors of the oil droplets on surfaces with different wettabilities at different flow velocities were observed as well. According to the adhesion behaviors of oil droplets on surfaces with different wettabilities, a mathematical model was established to analyze water film thinning and the adherence of oil droplets on the wall in the laminar flow field. Then the quantitative relationships among the adhesion times tf of oil droplets on different wetting surfaces, oil and water properties, and surface wettability were acquired.
研究领域:
流体力学
·
材料科学
·
界面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Zhongxiao Cong,Yuanfang Song,Yuxi Song,Ying Li,Ao Tang
The all-vanadium flow battery (VFB) is a promising candidate for long-duration energy storage. Flow field design is deemed as a critical approach to realize high power density operation for VFBs. However, conventional graphite bipolar plates still face mechanical limitations for practical stack uses, so there is an urgent need to explore alternative design strategies. Herein, a carbon paper based serpentine flow field (SFF) design is proposed for high power density VFB operation, which simultaneously reduces pressure drop and concentration polarization . Finite element analyses firstly compare different SFF designs and reveal effectively reduced pressure drop and promoted flow velocity across the electrode for 100 % SFF design. Subsequently, the 100 % SFF design presents significantly reduced concentration polarization at 200 mA cm −2 and 85 % SOC , which outperforms non-flow field and other SFF designs. Moreover, the full cell experiments demonstrate an enhanced voltage efficiency of 83.6 % at 200 mA cm −2 along with higher discharge capacity. By further coupling 100 % SFF with Bi catalyst, the VFB cell finally proves to deliver a 79 % voltage efficiency at 300 mA cm −2 and stably operate over 1000 cycles, which highlights the great potential of proposed design strategy to realize high power density VFB operations.
研究领域:
能源材料科学
·
电化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Danlong Li,Xiaokang Yan,Wenjian Wang,Hainan Wang,Ruoqian Zhou,Hanxi Yang,Haijun Zhang
Solid surface hydrophobicity plays a crucial role in flotation recovering valuable components from fine particles, which is generally rendered by reagent adsorption. In this work, to compare the liquid − solid mixing and particle surface modification performance of two different energy input forms induced by structure design, namely the mechanical agitation and hydrodynamic flow, which corresponded to a stirred tank (ST) and a novel conditioning device with opposite rotational flow (CDORF) without any agitation impellers, flow field simulations and conditioning − flotation tests were conducted, together with the particle characterization. Results showed that compared with the radial flow dominated ST, integrated forms of convection and shear mixing effectively promoted pulp homogenization in the CDORF. Basically, electrostatic attraction could be easily completed between the changed functional groups of Si − O − and RNH 3 + , but hydrogen − bond affinity occurred between the species of RNH 3 + and Si − OH or water molecules, thereby causing competitive adsorption to some extent, which required continuously transporting particles and reagent molecules through the area with high strain rate to clean particle surfaces and launch their interactions. Based on the simulation of particle distribution and strain rate, the CDORF exhibited compatible zones of large shear and dispersed particles. Therefore, it was found to obtain better response of the induction time and the flotation recovery of fine quartz particles per added power to the collector adsorption features. The research findings reveal that the collector − particle interaction between their functional groups could be flow field dependent, which is expected to provide references for designing and optimizing equipment related to flow process fields, especially in the solution containing surfactants.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-13
·
IF 15.7
Zhao Erzhuo,Zhang Yixin,Zhan Juhong,Xia Guangsen,Yu Gang,Wang Yujue
The recently developed porous solid electrolyte (PSE) reactor for electrosynthesis of hydrogen peroxide (H 2 O 2 ) has attracted significant global interest. However, scaling up the PSE reactor for practical applications poses challenges, particularly due to performance decline in enlarged reactors. Here we systematically investigate how factors such as material selection, assembly parameters, flow field patterns, and operating conditions influence H 2 O 2 electrosynthesis in the PSE reactor. Our findings reveal that the performance decline during reactor scale-up is primarily caused by the uneven flow field in the PSE layer. Based on these insights, we optimize the reactor design and develop a 12-unit modular electrode stack PSE reactor with a total electrode area of 1200 cm 2 . The scaled-up reactor maintains efficient H 2 O 2 electrosynthesis without significant performance decline. It operates stably for over 400 h and can produce up to 2.5 kg pure H 2 O 2 (~83 kg 3% H 2 O 2 solutions) per day with considerably lower energy costs (0.2‒0.8 USD/kg H 2 O 2 ) than the market prices of H 2 O 2 stocks. This work represents a crucial advancement in the development of PSE reactor technology for practical H 2 O 2 electrosynthesis.
研究领域:
化学工程
·
电化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2025
·
IF 4.6
Mianyan Yang,Zhijun Zhang
The critical flow velocity required to detach glass beads (soda-lime) of different hydrophobicity from bubbles was investigated. Using a home-made turbulence controlling system to observe the centrifugal motion of glass beads. The results indicated that different flow velocities were achieved by controlling the rotational speed. Different flow velocity indirectly affected the centrifugal acceleration when the centrifugal detachment of glass beads occurred. When the flow velocity exceeded the critical value, the different hydrophobic glass beads and bubble aggregates experienced centrifugal detachment force also reached the critical value. Due to the pinning effect, the more hydrophobic the glass beads attached to the bubbles, the more stable the aggregates formed. It was necessary to increase the flow velocity to enhance the centrifugal detachment force. The three-phase contact line (TPCL) between glass beads and bubbles rapidly slipped and contracted when attachment force was less than detachment force in centrifugal motion. Resulting in a noticeable necking phenomenon that completed the detachment. Meanwhile, the detachment behavior between glass beads and bubbles did not occur at specific locations, but rather randomly. It was depended on the size and strength of the vortex at that location, as well as the stability of attachment between bubbles and various glass beads.
研究领域:
流体力学
·
界面科学
✓ 已验证
产品关联
DOI
高影响因子
iScience
·
2022
·
IF 6.107
Yueying Liu,Zhenguo Jing,Qiang Liu,Ang Li,Wenwen Li,Sen Zhang,Ang Lee,Fu Tian,Rui Li,Wei Peng
An integrated aerodynamic three-hole pressure probe (THP) based on a fiber-optic tip sensor array for high-velocity flow field vector measurement is developed and demonstrated in wind tunnel testing. The sensor array consisting of three miniature pressure fiber-tip sensors is integrated into three pressure conduits inside top area of the THP, which serves to mitigate pneumatic pressure loss and is expected for a more reliable analysis of flow characteristics. Fast real-time data acquisition is implemented by a compact self-developed multichannel white light interferometry (WLI) interrogator. Well-calibrated maps of the fiber-optic THP are developed in a subsonic free-jet wind tunnel to derive the velocity vectors in a yaw angular range of ±15° at Mach numbers of 0.2 Ma (∼70 m/s), 0.5 Ma (∼170 m/s), and 0.8 Ma (∼300 m/s) while related flow characteristics are analyzed. This work is desired to provide a potential candidate for turbomachinery experimental investigation in fluid mechanics community.
研究领域:
流体力学
·
航空航天工程
✓ 已验证
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2022
·
IF 4.264
Zhangcheng Gao,Jianqing Wang,Lianfang Feng,Xueping Gu,Jintang Duan,Cailiang Zhang
Under the conditions specified in this work, the polycondensation reaction to prepare rigid rodlike poly(p-phenylene-cis-benzobisoxazole) (PBO) is diffusion-controlled. This work aims to study the flow-driven polycondensation reaction of PBO. The effect of mixing efficiency through changing the stirring speed on the polycondensation reaction of PBO was first investigated in a paddle impeller reactor (PIR). In the initial stage of polymerization, the increase of stirring speed is obviously conducive to accelerating the polycondensation reaction. However, the promoting effect of stirring speed on the polycondensation reaction is greatly reduced in the middle and late stages of polymerization. The effect of the flow pattern with different proportions of shear flow, elongational flow and rotational flow on the polycondensation reaction of PBO was further investigated by comparing three reactors including Couette-Taylor reactor (CTR) with a complete shear flow, PIR with strong shear and elongational flows, and double helical ribbon reactor (DHR) with strong shear and rotational flows. Result shows that the improvement of proportions of rotational flow and elongational flow is beneficial to accelerate the polycondensation reaction of PBO in the middle and late stages of polymerization, especially for the rotational flow.
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
Polymers
·
2023
·Vol. 15
·期 7
·1755
·
IF 5
Junyuan Zhang,Zilong Peng,Mengjie Wang,Yinan Li,Jinyin Wu,Yifan Jiang,Chaolong Liu,Guqiang Li,Lin Xu,Hongbo Lan
The fabrication of various 3D tissue engineering tubular scaffolds with fibrous structures, to assist the human body in rapidly repairing a variety of ailments, is receiving more and more attention. Due to the inefficiency of the majority of fibrous preparation techniques, the question of how to rapidly produce the requisite three-dimensional tubular microfiber scaffold structures has become an urgent problem. In this study, an efficient polymer fiber preparation method was developed, using a high-speed airflow drive. Melt blending of polycaprolactone (PCL), polylactic acid (PLA), and tributyl citrate (TBC), was used for the printing material, to achieve the efficient preparation of tubular microfiber scaffolds with different structures. The scaffold diameter was as small as 2 mm, the wall thickness was up to 100 μm, and the fiber injection efficiency reached 15.48 g/h. By utilizing simulations to optimize the printing parameters and by adjusting the printing settings, it was possible to achieve a controlled fiber diameter in the range of 3 μm to 15 μm. In addition, plasma treatment was applied to the microfibers’ surface, to increase their wettability, and the efficiency of the hydrophilic modification was demonstrated. Furthermore, the mechanical property test demonstrated that the fibers have a tensile strength of 1.36 ± 0.16 MPa and a tensile strain of 30.8 ± 3.5%. The radial compressive strain of the tubular scaffold could reach 60% of the original scaffold’s diameter. Finally, the in vitro degradation of the fibers at various pH values was tested. The results showed that, under alkaline conditions, the surface of the fibers would be severely crushed and the rate of deterioration would increase.Keywords:airflow-field-driven;3D printing;microfiber scaffold;polycaprolactone (PCL);polylactic acid (PLA)
研究领域:
组织工程
·
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）