Article
Engineering, Environmental
M. Gumulya, R. P. Utikar, V. K. Pareek, G. M. Evans, J. B. Joshi
Summary: 2D rectangular columns are often used for visualization and CFD studies of multiphase flows. In this study, a numerical analysis was conducted on the dynamics of a rising bubble within such a setup, indicating that the shape and motion of the bubble are influenced by the gap size and Reynolds number. Increasing Reynolds number results in a more elongated oblate spheroidal shape and predominantly rectilinear rise behavior of the bubble.
CHEMICAL ENGINEERING JOURNAL
(2021)
Review
Nuclear Science & Technology
Christian Mulbah, Can Kang, Ning Mao, Wei Zhang, Ali Raza Shaikh, Shuang Teng
Summary: This study summarizes recent developments of the VOF method and discusses coupling strategies with other specific methods. A comprehensive explanation of bubble behaviors is provided, while applications of the VOF method in describing various bubble characteristics are reviewed.
PROGRESS IN NUCLEAR ENERGY
(2022)
Article
Mechanics
Jun Xie, Liansheng Liu, Xinpeng Huo, Xuanchen Liu, Runze Duan
Summary: This study designed a swirl effervescent atomizer coupled with a wire mesh to investigate the influence of the wire mesh on spray characteristics and internal flow with different structural parameters. Results showed that installing a wire mesh improved spray quality and stability, with smaller droplet diameter and stable atomization. Simulation results indicated that increasing the effective porosity of the wire mesh resulted in a higher proportion of small-scale bubbles and reduced spray droplet diameter.
Article
Thermodynamics
Jinbiao Xiong, Hao Xie, Sijia Du, Xu Cheng
Summary: In this study, a wire mesh sensor was used to measure the two-phase flow of air and water in a pressurized water reactor fuel assembly. The results showed that the bubble size and gas superficial velocity affected the void fraction and bubble size distribution in the bare rod bundle. When a mixing-vane spacer grid was installed, the vortices induced bubble entrapment and enhanced the interaction between bubbles. Additionally, the vortices resulted in void drift of small bubbles between subchannels.
APPLIED THERMAL ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Haoran Zhou, Kai Meng, Wenshang Chen, Ben Chen
Summary: This study developed a volume of fluid (VOF)-coupled electrochemical method to investigate the evolution and transport characteristics of bubbles in the flow field of Proton Exchange Membrane Water Electrolyzer (PEMWE). The results show that bubbles undergo several processes and factors such as liquid water flow velocity, wall adhesion, and bubble accumulation in the outlet manifold affect the bubble removal rate.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Mathematics
Jinfeng Wang, Bingjun Wang, Jing Xie, Ke Lei, Bo Yu, Yuhang Sun
Summary: The study simulated three-dimensional subcooled flow boiling of R134a in a horizontal tube and explored bubble characteristics, identifying five representative bubbles. Results showed that bubble radial velocity is crucial for bubble departure, and heat flux, inlet velocity, and inlet subcooling all influence bubble departure diameter.
Article
Mechanics
Van-Tu Nguyen, Thanh-Hoang Phan, Trong-Nguyen Duy, Dong-Hyun Kim, Warn-Gyu Park
Summary: This study investigated the dynamic behavior of bubble collapses near walls and a free surface using numerical simulation, validating the results with experiments and providing important references for exploring phenomena related to bubble collapse.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Materials Science, Multidisciplinary
Xinkang Hu, Bo Zhang, Chundu Wu, Xiaohong Xu, Mingming Xue, Xiaoyong Zheng
Summary: In this study, a stable high-speed tangential liquid flow was obtained by combining the vortex supply chamber and the variable-diameter accelerated vortex cavitation reaction chamber, improving the cavitation effect inside the generator. The installation of the central air intake column above the cavitation reaction chamber prolonged the shear fracture time of bubbles under high shear force, improving the gas-liquid contact and mixing efficiency.
Article
Engineering, Chemical
Veerendra Kumar, Vinod Kumar Singh, Sanjeev Kumar, Gaurav Singhal
Summary: COIL is a chemical laser using singlet oxygen molecules as pumping species and iodine atoms as lasing species, with SOG as the heart of the device facilitating the reaction to produce singlet oxygen molecules. CBSOG is a potential alternative to SOG for high throughput and high power COIL systems, operating under gravity independent conditions. The performance of bubble formation and movement in the BHP layer significantly affects the COIL system, with numerical analysis and simulation results showing good agreement with experimental data.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Mechanics
Shuai Li, Youssef Saade, Devaraj van der Meer, Detlef Lohse
Summary: The Boundary Integral Method (BIM) has been widely used for simulating oscillating bubbles due to its efficiency and accuracy. A new model called CBIM has been proposed for bubbles in a weakly compressible flow. Comparison of BIM, CBIM, and AMM results show closeness at low Mach numbers, with deviations increasing at higher Mach numbers.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Mechanics
Stephane Perrard, Alienor Riviere, Wouter Mostert, Luc Deike
Summary: In this study, the deformation modes and lifetime of a bubble in a turbulent flow are investigated through numerical simulations and theoretical analysis. Two temporal regimes are observed during the bubble deformation process, with the first regime driven by inertial forces and the second regime resulting from a balance between inertial forces and surface tension.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Daniel J. Ruth, Marlone Vernet, Stephane Perrard, Luc Deike
Summary: The study shows that the average rising speed of bubbles in liquid decreases with increasing turbulence intensity, following a specific proportional relationship. This is mainly due to the effects of nonlinear drag and the nearly isotropic behavior of the slip velocity on the mean rise speed.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
Matthias Kramer, Daniel Valero
Summary: High-Froude-number flows become self-aerated when turbulence overcomes gravity and surface tension forces. Instead of using single-layer approaches, a new two-state formulation is presented to explain the complete air concentration profile through the weak interaction between turbulent boundary layer and turbulent wavy layer. The proposed flow conceptualization allows for more physically based numerical modeling of turbulent mass diffusion in self-aerated flows.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
D. Raciti, P. Brocca, A. Raudino, M. Corti
Summary: We present a new interferometric method to study the interactions between two gas bubbles in a liquid undergoing small-amplitude oscillations. The technique allows for accurate measurement of the amplitude, frequency, and phase of oscillation, as well as probing the interactions between the bubbles. This method is of great importance for understanding bubble interactions.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Alienor Riviere, Wouter Mostert, Stephane Perrard, Luc Deike
Summary: This study investigates the dynamics and statistics of bubble break-up in homogeneous and isotropic turbulence through direct numerical simulations, focusing on the influence of the Weber number on bubble break-up dynamics. The findings reveal that during the transition to stable conditions, bubble break-up occurs through both local and non-local production processes, resulting in a range of bubble sizes.
JOURNAL OF FLUID MECHANICS
(2021)