Article
Mechanics
Md Ashraful Islam, Albert Y. Tong
Summary: This study numerically analyzed the dynamics of drop formation from a vertical capillary tube, identifying the mechanism of satellite drop formation and liquid filament recoiling after droplet detachment. Parametric studies showed that inlet velocity, surface tension coefficient, and viscosity play important roles in satellite droplet generation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Engineering, Environmental
Langyu Liu, Shaokun Jiang, Chunying Zhu, Youguang Ma, Taotao Fu
Summary: The experimental study focused on the liquid-liquid distribution and droplet dynamics in branching T-junction microchannels. Different droplet flow patterns were identified in the main channel and the effects of flow rates and crossing flow on two-phase distribution were described. The analysis and prediction of two-phase distribution achieved a good prediction effect on liquid-liquid two phases distribution in branching microchannels.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Yanpeng Dong, Chunying Zhu, Youguang Ma, Taotao Fu
Summary: This study investigates the distribution of liquid-liquid two-phase flow and droplet dynamics in asymmetric parallel microchannels using a high-speed camera. It explores the factors affecting droplet stability and uniformity, and designs microfluidic devices with different configurations to examine their effects on flow distribution. Additionally, a prediction for the distribution of liquid-liquid two-phase flow under slug flow is proposed based on the principle of hydrodynamic resistance.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Mechanics
Weidong Yu, Shinan Chang, He Song
Summary: This study numerically investigates head-on ternary droplet collision of the same liquid in a gaseous environment. The shape and velocity field evolution of three colliding droplets are studied for a wide range of Weber number. Relevant correlations for the length and diameter of the ligament, length of the bridge, and maximum radial length are presented quantitatively based on the dimensionless flow parameters.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Thermodynamics
Konstantinos Vontas, Manolia Andredaki, Anastasios Georgoulas, Nicolas Miche, Marco Marengo
Summary: This paper conducts an advanced numerical investigation on the effect of surface wettability characteristics on bubble growth within microchannels. The results demonstrate a significant impact of surface wettability on heat transfer coefficients, with hydrophilic and hydrophobic surfaces outperforming single-phase reference simulations by approximately 43.9% and 17.8% respectively.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Energy & Fuels
Konstantinos Vontas, Manolia Andredaki, Anastasios Georgoulas, Nicolas Miche, Marco Marengo
Summary: The study numerically investigated the flow boiling characteristics in rectangular microchannels of varying hydraulic diameters, finding that having parallel microchannels configuration can significantly reduce the average thermal resistance.
Article
Engineering, Marine
N. Karimi Asli, M. Rahmanpour, A. H. Mosaffa
Summary: In this study, a two-dimensional numerical model based on the realizable k-epsilon turbulent model was established to simulate the water entry and immersion process of three steel pipes attached to a concrete base. The effects of Froude Number on penetration depth and impact force were investigated. The numerical analysis revealed that the maximum force applied to the base of the structure increases suddenly with the increase of Froude Number and contact surface.
Article
Thermodynamics
Konstantinos Vontas, Nicolas Miche, Marco Marengo, Anastasios Georgoulas
Summary: This study investigates the effect of solid surface thermophysical properties on flow boiling heat transfer characteristics within micro-channels using numerical simulations. The results show that materials with higher thermal conductivity exhibit higher heat transfer coefficients, indicating the significant influence of solid surface properties on heat transfer in flow boiling.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Daniel Klembt, Heiko Meironke, Antonio Delgado
Summary: This experimental research aims to measure and simulate a biological multiphase flow in a fermentation tank, focusing on the complex interactions between three phases and the disturbance of natural convection by rising gas bubbles in high turbid fluid. The study uses acoustic sensors instead of optical measurement, and improves measurement technique for direct correlation between temperature and flow fields.
APPLIED THERMAL ENGINEERING
(2021)
Article
Mechanics
Jean Cappello, Javier Rivero-Rodriguez, Youen Vitry, Adrien Dewandre, Benjamin Sobac, Benoit Scheid
Summary: This paper experimentally characterizes the equilibrium velocity and lateral position of dispersed micro-objects in a cylindrical microchannel. It explores the dynamics of non-deformable viscous objects and deformable inertial objects, and proposes a correlation model for object velocity.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Zhongdong Wang, Xingyu Xiang, Sajawal Raza, Asad Ullah, Chunying Zhu, Tianyang Feng, Youguang Ma, Taotao Fu
Summary: This paper investigates the emulsification process and numbering-up of droplets in asymmetric parallelized microchannels with T-junction. It analyzes the effects of fluid properties and operating conditions on droplet size. The paper also examines the flow patterns of droplet swarm in cavities and their influence on fluid distribution. It proposes a droplet size prediction equation and fluid distribution model, and investigates the phenomenon of droplet asynchronous generation and its effect on droplet monodispersity, suggesting a method for prevention.
JOURNAL OF FLOW CHEMISTRY
(2023)
Article
Engineering, Chemical
Venu Kondala Rao Angirekula, Raghvendra Gupta
Summary: Microreactors are a viable option for gas-liquid reactions with limited mass transfer, thanks to their high gas-liquid interfacial area density. This study investigates the hydrodynamics of axisymmetric gas-liquid annular flow in millimeter-size channels using computational fluid dynamics methods. The research reveals the presence of coalescing and non-coalescing waves at the interface and examines the impact of gas and liquid flow rates on the wave characteristics.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2022)
Article
Mechanics
Sofia Angriman, Amelie Ferran, Florencia Zapata, Pablo J. Cobelli, Martin Obligado, Pablo D. Mininni
Summary: This study investigates the three-dimensional clustering of velocity stagnation points, vorticity nulls, and inertial particles in turbulent flows with different large-scale flow geometries by combining direct numerical simulations and particle tracking velocimetry. The results show that although the flows have different topologies in terms of null clustering, the behavior of particles is similar in all cases, indicating the clustering of Taylor-scale neutrally buoyant particles as inertial particles.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Chemistry, Multidisciplinary
Li Lei, Yuting Zhao, Jun An, Bo Zhang, Jingzhi Zhang
Summary: The experimental method was used to study the droplet breaking characteristics of a two-phase immiscible liquid-liquid system in symmetric Y-junction microchannels. The results showed that the breakup behavior of the droplets had an impact on the flow pattern and the length of the sub-droplets. A correlation formula for predicting the length of the sub-droplets was proposed.
APPLIED SCIENCES-BASEL
(2022)
Article
Thermodynamics
Hao Ma, Zhipeng Duan, Xiaoru Ning, Liangbin Su
Summary: The study reveals that Reynolds number has a significant impact on the local Nusselt number in the thermally developing region while being independent of the developed Nusselt number. Additionally, the local Nusselt number increases with decreasing aspect ratio.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Engineering, Mechanical
Syed Ahsan Sharif, Mark Kai Ming Ho, Victoria Timchenko, Guan Heng Yeoh
Summary: In this paper, the growth of a rising vapor bubble in superheated water was numerically studied using an advanced interface tracking method. The simulation considered convective heat transfer and phase-change mechanisms. The results showed good agreement with analytical and past works.
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Mathematics, Interdisciplinary Applications
Darson D. Li, Qing N. Chan, Victoria Timchenko, Guan H. Yeoh
Summary: A computational model is developed to evaluate two novel strategies in controlling the aggregation behavior of magnetic-responsive particles. Under a static magnetic field, particles form chain-like structures; under a rotating magnetic field, particle aggregation is encouraged, leading to longer chain-like structures; under an alternating magnetic field, complete particle disaggregation is observed periodically.
COMPUTATIONAL PARTICLE MECHANICS
(2022)
Article
Biochemistry & Molecular Biology
Timothy Bo Yuan Chen, Ivan Miguel De Cachinho Cordeiro, Anthony Chun Yin Yuen, Wei Yang, Qing Nian Chan, Jin Zhang, Sherman C. P. Cheung, Guan Heng Yeoh
Summary: A multi-scale modelling framework was proposed in this study to simulate the pyrolysis process of polymer composites using Molecular Dynamics models and Computational Fluid Dynamics fire model. The results showed the potential application of the developed model in predicting toxic gas emissions during polymer decomposition.
Article
Green & Sustainable Science & Technology
Zibo Zhou, Svetlana Tkachenko, Prateek Bahl, Dana Tavener, Charitha de Silva, Victoria Timchenko, Jessica Yajie Jiang, Mark Keevers, Martin Green
Summary: This study investigates a potentially cost-effective method for lowering the temperature of photovoltaic (PV) modules. The use of vortex generators (VGs) on the rear surface of the module is shown to effectively reduce the operating temperatures by enhancing the convective flux. Computational fluid dynamics simulations and measurements confirm the importance of VG shapes and placement in the formation of vortices and the improvement of convection.
Article
Chemistry, Multidisciplinary
Imrana I. Kabir, John C. Osborn, Weijian Lu, Jitendra P. Mata, Christine Rehm, Guan H. Yeoh, Tunay Ersez
Summary: The study revealed the aggregation of nanodiamond particles and the ellipsoidal structure of ND particles through SANS measurements. The contrast variation technique was useful in characterizing the non-diamond outer shell of the particles and determining the outer layer thickness. Understanding the structure of NDs at multiple length scales is crucial for various applications and for studying particle-particle interactions and aggregation structures.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2022)
Article
Thermodynamics
Hengrui Liu, Ivan Miguel De Cachinho Cordeiro, Anthony Chun Yin Yuen, Qing Nian Chan, Sanghoon Kook, Guan Heng Yeoh
Summary: A new predictive fire suppression model has been developed and applied to analyze the suppression mechanisms of water mist and sprinkler systems. The efficiencies and effectiveness of both systems were investigated, and their performance was evaluated. The study finds that water mist systems outperform sprinkler systems in terms of time and utilization rate, while sprinkler systems have a larger effective suppression coverage area.
NUMERICAL HEAT TRANSFER PART A-APPLICATIONS
(2023)
Article
Electrochemistry
Ao Li, Anthony Chun Yin Yuen, Wei Wang, Jingwen Weng, Chun Sing Lai, Sanghoon Kook, Guan Heng Yeoh
Summary: This study proposes a three-dimensional thermal model to simulate the thermal propagation effect inside battery packs, aiming to improve the thermal management performance of batteries. The results show that different abnormal heat locations have different impacts on the surrounding coolant and other cells. Based on the current battery pack setups, the maximum temperature of Row 2 cases may increase, along with an increase in temperature difference.
Article
Nuclear Science & Technology
Syed Ahsan Sharif, Mark Kai Ming Ho, Victoria Timchenko, Guan Heng Yeoh
Summary: In this study, a simulation of the condensation of a rising vapor bubble in subcooled boiling flow was performed using the InterSection Marker (ISM) method, an interface tracking method developed by the authors. The ISM method was coupled with an in-house variable-density and variable-viscosity single-fluid flow solver using the immersed boundary method. The condensation process was simulated by modeling source terms in the Computational Fluid Dynamics (CFD) governing equations. The simulation predicted the condensing bubble properties for different initial bubble sizes and liquid subcooling values and showed good agreement with previous studies, demonstrating the ISM method as an efficient, reliable, and viable tool for multiphase flow simulations involving heat and mass transfers across the interface.
NUCLEAR ENGINEERING AND DESIGN
(2023)
Article
Engineering, Manufacturing
Zhao Sha, Xinying Cheng, Yang Zhou, Andrew N. Rider, Andrew D. M. Charles, Wenkai Chang, Shuhua Peng, May Lim, Victoria Timchenko, Chun H. Wang
Summary: RF induction compatible self-healing composites were developed by hybridizing iron oxide nanoparticles and carbon fiber veils in poly(ethylene-co-methacrylic acid) (EMAA), resulting in enhanced magnetic and electrical properties. The multiscale conductive networks created by Fe3O4 nanoparticles and CFVs led to an improved electrical conductivity and heating efficiency. Additionally, the combination of Fe3O4 nanoparticles and CFVs significantly improved the bonding strength of EMAA polymer, making it suitable for various applications such as self-healing and reversible bonding.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Chemistry, Physical
Declan Finn Keogh, Mark Baldry, Victoria Timchenko, John Reizes, Chris Menictas
Summary: Liquid metal batteries (LMBs) are influenced by the interaction of thermal, compositional, and electromagnetic forces, and a three-layer numerical model was developed to investigate this behavior. The results showed that thermal convection was suppressed by electro-vortex flow and swirl flow induced by a background magnetic field. Compositional gradients in the cathode had a significant impact on the flow, highlighting the challenge of mixing in large-scale LMBs.
JOURNAL OF POWER SOURCES
(2023)
Article
Biochemistry & Molecular Biology
Imrana I. Kabir, Juan Carlos Baena, Wei Wang, Cheng Wang, Susan Oliver, Muhammad Tariq Nazir, Arslan Khalid, Yifeng Fu, Anthony Chun Yin Yuen, Guan Heng Yeoh
Summary: The effect of varying the weight percentage composition of low-cost expandable graphite, ammonium polyphosphate, fibreglass, and vermiculite in polyurethane polymer was studied. The synergistic effect between these components on the flame retardant properties of the PU composites was investigated. The PU composites containing 40 wt.% expandable graphite showed superior flame retardant performance.
Article
Ecology
Timothy Bo Yuan Chen, Anthony Chun Yin Yuen, Ivan Miguel De Cachinho Cordeiro, Hengrui Liu, Ruifeng Cao, Amy Ellison, Guan Heng Yeoh
Summary: The demand for underground railways has increased rapidly due to urbanization and population growth, emphasizing the need for tunnel designs with adequate fire safety measures. However, the complexity of modern rail tunnel designs makes it difficult to implement prescriptive codes and often leads to overly conservative designs. This study reviews the current state of tunnel fire analysis, focusing on Australia. A large-eddy simulation-based fire model is used to investigate the temperature and smoke dispersion in a 2 MW metro tunnel fire case scenario. The results suggest the need for revision of current tunnel fire standards and response protocols.
Article
Ecology
Ivan Miguel De Cachinho Cordeiro, Hengrui Liu, Anthony Chun Yin Yuen, Timothy Bo Yuan Chen, Ao Li, Cheng Wang, Ruifeng Cao, Guan Heng Yeoh
Summary: This study establishes a database to investigate the suppression effects of water-based suppression systems under different configurations and fire locations. The results show that the water mist system can effectively control fires above 200 degrees Celsius with a relatively short suppression time.
Article
Ecology
Preety Moni Doley, Anthony Chun Yin Yuen, Imrana Kabir, Luzhe Liu, Cheng Wang, Timothy Bo Yuan Chen, Guan Heng Yeoh
Summary: The smoke toxicity and fire risk of seven commonly used building polymers were analyzed using a systematic fire performance evaluation system. The results showed variations in smoke toxicity and fire risk among different polymers under different fire conditions.
Article
Electrochemistry
Ao Li, Anthony Chun Yin Yuen, Wei Wang, Timothy Bo Yuan Chen, Chun Sing Lai, Wei Yang, Wei Wu, Qing Nian Chan, Sanghoon Kook, Guan Heng Yeoh
Summary: The increasing popularity of lithium-ion battery systems has led to a growing interest in optimizing their performance, thermal stability, and fire safety, especially in electric vehicles and energy storage systems. This paper presents a comprehensive investigation of the temperature distribution and heat exchange process in battery packs using a three-dimensional electro-thermal model coupled with fluid dynamics. The results demonstrate the effectiveness of an artificial neural network model for optimizing battery design and achieving a decrease in maximum temperature and temperature difference. The simulation results provide practical guidance for optimizing battery configuration and cooling efficiency, while ensuring safety performance. The innovative approach of utilizing high-fidelity electro-thermal/CFD numerical inputs for ANN optimization has the potential to enhance thermal management and reduce the risks of thermal runaway and fire outbreaks.
Article
Engineering, Mechanical
Budi Rochmanto, Hari Setiapraja, Ihwan Haryono, Siti Yubaidah
Summary: This study calibrates a turbine flowmeter for compressed natural gas (CNG) application by using air as a substitute and simulating the kinematic viscosity property of CNG. The research shows that by using air instead of CNG, the flowmeter can achieve accurate measurements with a measurement uncertainty of less than 1%.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Mona Mary Varghese, Chaithanya P. Devan, Samiksha M. Masram, Teja Reddy Vakamalla
Summary: This work investigated the influence of particle shape on fluidization behavior at different inlet superficial gas velocities. The experiments were conducted using a laboratory-scale 3D circular fluidized bed column with Geldart D particles of various shapes. The results showed that non-spherical particles had lower minimum fluidization velocities and higher bed expansion compared to spherical particles. Particle shape significantly affected solids holdup, with spherical particles exhibiting higher solids holdup at the same superficial velocity. Frequency domain analysis of pressure signals using Fast Fourier Transform (FFT) and Power Spectral Density (PSD) revealed flow regime transitions associated with changes in particle shape.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Ruiming Yu, Yunyan Ma, Kuaile Liu, Xiangyu Liu
Summary: A single-seat control valve with stable flow regulation is researched and designed to address technical problems such as unstable flow at small openings and uneven force on the valve core. The mechanical and flow characteristics, as well as thermal stress, are analyzed through simulations and tests. The results show that the designed valve meets the requirements.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Alcemir Costa de Souza, Ewerton Emmanuel da Silva Calixto, Fernando Luiz Pellegrini Pessoa, Valeria L. da Sila, Luiz Octavio Vieira Pereira
Summary: This study proposes a simple CO2 meter for accurately measuring the CO2 content in Brazilian pre-salt production flows. By analyzing the pressure change during a heating assay of an imprisoned sample, the proposed meter is capable of identifying the mixture properties under different CO2 levels.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)
Article
Engineering, Mechanical
Mehdi Asadi, S. Abbas Hosseini, Kaveh Ahangari
Summary: Due to technical issues with bottom intake racks, porous intakes made of rock, gravel, or sand can be a viable alternative. This study used an experimental model to assess the performance of porous bottom intakes (PBI) and examined the impacts of various parameters such as channel slope, grain size distribution of the porous media, intake structure geometry, and water depth in the channel on diverted flow rates during sediment-free flow. The study also compared the performance of one-sided and three-sided PBI models under the same conditions. The findings suggest that a slope of 1% yields higher discharge coefficient and diverted flow compared to a slope of 1.68%, and three-sided PBI models outperform one-sided models in terms of flow rate. A formula utilizing nonlinear multivariate regression, experimental data, and dimensional analysis was proposed for calculating the discharge coefficient of PBI, with a high accuracy rate of over 95%.
FLOW MEASUREMENT AND INSTRUMENTATION
(2024)