Article
Chemistry, Analytical
Xiaopeng Shang, Xiaoyang Huang
Summary: This work presents experimental and numerical studies on the dynamics of cavitation bubbles in a nozzle-shaped microfluidic channel with PZT actuations. It is found that a cloud of bubbles can be generated near the center of the microfluidic channel when the actuation voltage is larger than a threshold at 1 kHz. The bubbles oscillate radially with expansion and compression, and translate upstream towards the opening of the nozzle. The bubbles undergo frequent coalescence and breakup, leading to vigorous churning of surrounding liquids. Numerical simulation shows a low-pressure zone inside the microfluidic channel within each cycle of the actuation period, which is responsible for bubble generation observed in the experiments. The method of bubble generation in this study is novel and can be applied for the enhancement of heat and mass transfer in microfluidic operations.
Article
Engineering, Chemical
Lin Sheng, Yuchao Chen, Jian Deng, Guangsheng Luo
Summary: This work reports the generation of short bubbles with high frequency in a capillary embedded step T-junction microdevice for gas-liquid process intensification. The specific surface area of the generated gas-liquid microdispersion system is larger than 10,400 m(2)/m(3), and the bubble formation mechanism is mainly driven by the relatively higher pressure drop providing a much higher breakup force for the squeezing flow.
Article
Materials Science, Multidisciplinary
Shifu Chen, Hong Lei, Hanchuang Hou, Changyou Ding, Han Zhang, Yan Zhao
Summary: Removing inclusions from molten steel using RH vacuum refining is crucial in producing high-quality steel products. Research shows that argon bubbles significantly enhance the transport and collision-coalescence of inclusions.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Engineering, Chemical
Yingjie Fei, Chunying Zhu, Taotao Fu, Xiqun Gao, Youguang Ma
Summary: The study investigated the breakup flow patterns, neck dynamics and tip dynamics of bubbles stabilized by adsorptive nanoparticles in a microfluidic Y-junction. It found that nanoparticles make bubbles more difficult to breakup, and the breakup process can be divided into squeezing, transition and pinch-off stages. The difference between hardening bubbles and conventional bubbles weakens as the dispersion flow rate increases.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Chemistry, Applied
Boxin Deng, Karin Schroen, Jolet de Ruiter
Summary: During foaming, bubble formation and stability are influenced by emulsifier adsorption. A microfluidic device is used to study bubble formation and coalescence dynamics, as well as bubble properties, which can indicate emulsifier adsorption. The study shows that the concentration of sodium dodecyl sulfate (SDS) affects bubble formation time and size, with different effects at low and high pressures. In addition, different emulsifiers show varying efficiency in suppressing bubble coalescence. Understanding and manipulating emulsifier adsorption is crucial for explaining foam product properties.
FOOD HYDROCOLLOIDS
(2023)
Article
Chemistry, Physical
Ivan U. Vakarelski, Farrukh Kamoliddinov, Sigurdur T. Thoroddsen
Summary: This study investigates the interaction between millimeter-sized bubbles and the seawater-air interface in seawater samples collected from the Red Sea coastal area. It demonstrates that high concentrations of electrolytes and organics in seawater do not affect the mobility of the bubble interfaces during free-rise and bouncing.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Engineering, Chemical
Siddharth Khadiya, Sadhana Kumari, Raghvendra Gupta
Summary: Gas-liquid flow in microchannels is important for various microfluidic applications, and the behavior of bubbles in microchannels is influenced by gas and liquid flow rates. Numerical simulations using the VOF method can provide insights into the dynamics of interacting bubbles and the evolution of their interfaces.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Sandra Orvalho, Petr Stanovsky, Marek C. Ruzicka
Summary: Experimental study on the coalescence of air bubbles in aqueous solutions of electrolytes reveals that the coalescence efficiency decreases with electrolyte concentration and bubble velocity, while the contact time decreases with bubble velocity but increases with electrolyte concentration. The transition from coalescence to noncoalescence proceeds via a minimum in the T(V) graphs, and bubble size affects the extent of the coalescence region.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
Boxin Deng, Karin Schroen, Jolet de Ruiter
Summary: Dynamic adsorption effects play a crucial role in bubble formation and stabilization, with bubble size depending on the interplay between time scales for bubble formation and protein adsorption. Experimental findings show two distinct bubble formation regimes, separated by a pressure difference of 1400 mbar, with different behaviors observed below and above this threshold.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2021)
Article
Engineering, Chemical
Yan Pang, Yao Lu, Xiang Wang, Qiang Zhou, Yanlin Ren, Zhaomiao Liu
Summary: Experimental study was conducted on bubble size in T-junction microchannels under pressure-driven conditions, showing that bubble length increases with flow rate and driving pressure. Different downstream channel types directly influence bubble size by affecting resistance, with a nonlinear relationship observed between them. Adjustment of flow rate at downstream provides feedback to bubble generation in the double T-junction channel.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Mechanics
Zhibin Wang, Jingyi Qin, Hongshi Su, Songping Mo, Ying Chen, Xianglong Luo
Summary: In this study, numerical simulations were used to investigate the core release characteristics of double-emulsion droplets. It was found that the initial core release may be interrupted by the retraction of the middle phase under certain conditions. Four core release types were identified, and a phase diagram summarizing these types was obtained. The results of this study have profound guiding significance for the application and understanding of double-emulsion droplets' release properties.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Mechanics
Gesse Roure, Alexander Z. Zinchenko, Robert H. Davis
Summary: In this paper, a boundary-integral method is developed to simulate the motion of drops in microchannels with arbitrary geometries. The results show that scaling with maximum vs average velocities can accelerate the convergence of the simulation. Non-regular geometries can affect drop partitioning and introduce challenges when comparing results for different depths. Inertial effects on undisturbed flow are small for moderate Reynolds numbers.
Article
Mechanics
Dege Li, Haoren Li, Guodong Yang, Yi Cao, Bingfang Huang, Xinlei Wu, Qiang Sun, Chi Ma, Yu Zhou, Yonghong Liu, Yanzhen Zhang
Summary: This study proposes a confined interface vibration inkjet printing technique that allows for printing patterns in a liquid environment with smaller droplet sizes. By adjusting the intensity of the pulse stimulation, the size and quantity of the dispensed droplets can be controlled, enriching the fundamental theory of inkjet printing in liquid phase.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Majid Rodgar, Helene Scolan, Jean-Louis Marie, Delphine Doppler, Jean-Philippe Matas
Summary: The study experimentally examined the behavior of a bubble injected into a horizontal liquid solid-body rotating flow, showing how factors such as bubble size, rotation speed, and buoyancy impact the bubble's aspect ratio and movement. The study also found that at certain extreme conditions, such as when the Reynolds number exceeds 3000, the bubble can experience abrupt transitions and potentially break up due to resonance between the periodic forcing of the rotating cell and the eigenmodes of the stretched bubble.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Biochemical Research Methods
Loic Chagot, Cesar Quilodran-Casas, Maria Kalli, Nina M. Kovalchuk, Mark J. H. Simmons, Omar K. Matar, Rossella Arcucci, Panagiota Angeli
Summary: The control of droplet formation and size using microfluidic devices is essential for laboratory and industrial applications. This study investigates how surfactants can improve stability and control droplet size in silicone oil. Two data-driven models, based on Bayesian regularised artificial neural network and XGBoost, accurately predict droplet size as a function of flow rates and surfactant properties. Compared to semi-empirical models, the data-driven models have higher accuracy. The models were also trained with simplified inputs, showing good prediction results. Additionally, a synthetic data set was generated, proving the feasibility of using this method in future lab on a chip applications.
Article
Thermodynamics
Daofan Ma, Chunying Zhu, Taotao Fu, Xigang Yuan, Youguang Ma
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2020)
Article
Engineering, Chemical
Shizhe Zhang, Chunying Zhu, Huisheng Feng, Taotao Fu, Youguang Ma
Summary: The study found that sudden expansion structures can significantly enhance gas-liquid mass transfer; the enhancement factor increases with the number of sudden expansion units and gas-liquid flow rate ratio, while pressure drop shows only slight elevation; the effective mass transfer enhancement efficiency was assessed based on energy consumption and enhancement factor.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Agricultural Engineering
Yuying Hu, Xiaohuan Zheng, Shihao Zhang, Wenjie Ye, Jing Wu, Souhila Poncin, Huai Z. Li
Summary: High solid anaerobic digestion (HSAD) is a potential organic waste treatment method with advantages of small footprint, less digestate, and low heating energy. Studying the hydrodynamics of HSAD showed that optimizing mixing can greatly increase its processing capacity.
BIORESOURCE TECHNOLOGY
(2021)
Article
Engineering, Chemical
Daofan Ma, Di Liang, Chunying Zhu, Taotao Fu, Youguang Ma, Xigang Yuan, Huai Z. Li
Summary: The study visually investigated the breakup process of viscous droplets in Y-shaped microchannels, highlighting the dynamics of droplet breakup with partial obstruction. The rupture process of droplets is divided into squeezing, transition, and rapid pinch-off stages, each displaying unique characteristics related to time, two-phase viscosity ratio, capillary number, and other factors. The findings provide insights into the factors influencing droplet breakup in microscale flow systems.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Environmental
Yuying Hu, Shihao Zhang, Xin Wang, Xiaoming Peng, Fengping Hu, Chuqiao Wang, Jing Wu, Souhila Poncin, Huai Z. Li
Summary: This study proposed a novel approach for experimentally quantifying the mass transfer in the mixing process of HSAD using the Laser Induced Fluorescence technique. The results showed that the feedstock tended to accumulate around the impeller in the HSAD system, and diffusion around the 1st impeller was rapid while around the 2nd impeller was tough. Prolonging mixing time did not significantly improve the flow pattern and mixing in HSAD.
Article
Engineering, Chemical
You Ma, Chunying Zhu, Taotao Fu, Youguang Ma, Huai Z. Li
Summary: The dynamics of non-Newtonian droplet breakup in a microfluidic Y-junction with partial obstruction was visually investigated. Three breakup stages were identified: squeezing, transition, and pinch-off. Factors such as the concentration of CMC, continuous capillary number, and dispersed phase local capillary number were found to affect the breakup process, with the pinch-off stage primarily determined by surface tension.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Xiaofeng Jiang, Shixing Chen, Enle Xu, Xianliang Meng, Guoguang Wu, Huai Z. Li
Summary: This study investigates the downhill motion of liquid drops and liquid marbles using two distinct particle-laden interfaces. It is found that liquid marbles have a lower velocity than liquid drops but a higher maximum aspect ratio, indicating different interactions due to particles present on different surfaces.
Article
Agricultural Engineering
Fengping Hu, Shihao Zhang, Xin Wang, Chuqiao Wang, Jing Wu, Souhila Poncin, Li Xu, Gaoping Xu, Yuying Hu, Huai Z. Li
Summary: The study investigates the impact of impeller width on the correlation of mixing-fluidity-energy at different rotating speeds, as well as the scale-up effect based on rotating speed and a generalized Reynolds number. Results show that impeller widths of 100 mm (10 rpm), 200 mm, and 300 mm (5 and 10 rpm) are preferred for improving hydrodynamics and energy efficiency in HSAD. Additionally, the study suggests that Reynolds number similarity has significant implications for scale-up applications in practical engineering.
BIORESOURCE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Olfa Beji, Nouceiba Adouani, Souhila Poncin, Huai-Zhi Li
Summary: Biogas production from anaerobic digestion of different wastes is of growing interest in renewable energy. This study investigates the use of liquid digestate and slurry as substrates for microalgae-bacterial flocs growth and methane production. The results showed that 30% dilution of digestate and 10% dilution of slurry were optimal for nutrient removal and biomass production. The anaerobic digestion without flocs performed better in terms of methane production compared to digestion with flocs.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Xiaofeng Jiang, Yi Zhou, Enle Xu, Xiangliang Meng, Guoguang Wu, Huai Z. Li
Summary: The impact of water drops on superhydrophobic surfaces (SHSs) with or without cavities was experimentally investigated in this study. Compared to plane SHSs, the cavity with different geometries reduces the maximum spreading diameter and contact time, and leads to complex drop deformation under higher We numbers. The dimensionless contact time on plane SHSs remains constant at about 0.88, while that on the cavity-textured SHSs is about 0.82. The drop impact on SHSs with macro-textured cavities exhibits different behaviors, which is important for applications such as self-cleaning and anti-icing.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Chemistry, Multidisciplinary
Qindan Zhang, Souhila Poncin, Christian Blanchard, Youguang Ma, Huai Z. Li
Summary: The coalescence behavior of ferrofluid drop on its bulk surface was studied experimentally using a high-speed camera. Shape deformations of both the pendant ferrofluid drop and the bulk surface were observed in the axial direction during the approaching process, even without a magnetic field. The angle of the upper pendant peak decreases with increasing magnetic flux density, while the lower ferrofluid peak shows the opposite trend. The coalescing width of the ferrofluid drop follows a power-law relationship.
Article
Engineering, Chemical
Hao Jiang, Chunying Zhu, Taotao Fu, Xiqun Gao, Youguang Ma, Huai Z. Li
Summary: A new droplet sieving method using grooved microchannel is proposed for achieving droplet monodispersity. The sieving performance and mechanism are experimentally investigated, revealing three different sieving flow regimes: incomplete sieving, complete sieving, and main droplet rupture. The effects of different operating conditions on sieving efficiency are systematically studied.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Review
Engineering, Chemical
Dong Lin, Zhiwei Mao, Jingyuan Shang, Huihong Zhu, Tiebin Liu, Yining Wu, Huai Z. Li, Chong Peng, Xiang Feng
Summary: The second-generation biodiesel, generated through the deoxygenation of vegetable oils, is an ideal green fuel that can help address environmental pollution and the energy crisis. This review summarizes the catalyst design strategies, including the selection of metal active species, adjustment of coordination environment, and regulation of the metal-support interface, to provide insights into the catalytic mechanisms and guide the synthesis of catalysts for the deoxygenation of vegetable oils, promoting the industrialization process of second-generation biodiesel.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Biochemical Research Methods
C. Y. Tong, Huai Z. Z. Li, C. J. C. Derek
Summary: This study investigates cell detachment of Chlorella vulgaris from porous substrates in early cultivation stage using a microfluidic platform. Results show that increasing flow velocity enhances nutrient transport but also triggers cell detachment. The effect of flow velocity on cell detachment differs at different locations. These findings contribute to optimizing operating conditions and reactor design for algae cultivation systems.
Article
Engineering, Chemical
Zhiwei Zhang, Shaokun Jiang, Chunying Zhu, Youguang Ma, Taotao Fu
CHEMICAL ENGINEERING SCIENCE
(2020)
