Article
Mechanics
Lei Han, Liang Hao, Jin Zhu, Mindi Zhang, Biao Huang
Summary: The objective of this study was to investigate the coupled dynamics of a collapsing bubble and the motion of a nearby elastic plate at different initial distances. Using both experimental and computational models, the researchers recorded the temporal and spatial evolution of a collapsing bubble near an elastic boundary. The results show that the behavior of the bubble, including oscillation time, impact mode, and energy conversion, varies with different initial distances, influenced by the elastic rebound of the plate.
Article
Engineering, Mechanical
Renshi Zheng, Xiaoyu Zhao, Leilei Dong, Gang Liu, Yi Huang, Yunze Xu
Summary: This study investigates the cavitation erosion-corrosion performances of X65 pipeline steel at different locations of a Venturi pipe. The results demonstrate that the collapse of bubbles at throat downstream leads to pitting damage, thereby accelerating localized corrosion. Cavitation erosion is solely induced by corrosion enhanced erosion at the employed flow rate. Local hardness degradation and crack initiation at anodic sites are the two fundamental requirements for erosion to occur. Along with the formation of deep pits, the fracture of the steel substrate at the pit boundary becomes the primary contributor to erosion, which is induced by repeated bubble collapse and corrosion assistance. The synergy of corrosion and cavitation erosion is the main cause of steel failure in the Venturi pipe.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Engineering, Mechanical
Janusz Steller
Summary: The author proposed a fractional approach to model cavitation erosion kinetics over two decades ago in response to issues in material resistance assessments from the International Cavitation Erosion Test project. The current status, potential, and limitations of the methodology were summarized in a paper published by Wear in 2020, along with details of the computational algorithm and examples illustrating the methodology description. Prospects for further development of the methodology are discussed in the paper.
Article
Acoustics
Fabian Reuter, Carsten Deiter, Claus -Dieter Ohl
Summary: This study reveals the mechanism behind energy focusing during the non-spherical collapse of cavitation bubbles, leading to the erosion of hardened metals. Using high-speed imaging and shockwave recording, the conditions for this focusing process and its damage to solids are resolved.
ULTRASONICS SONOCHEMISTRY
(2022)
Article
Mechanics
Theresa Trummler, Steffen J. Schmidt, Nikolaus A. Adams
Summary: The collapse behavior of cavitation bubbles near walls under high ambient pressure conditions was studied by numerical simulation. It was found that the stand-off distance has significant effects on collapse dynamics, micro-jet formation, rebound, and maximum wall pressure. The study also analyzed the resolution dependence of collapse and rebound, as well as the observed maximum pressure distributions.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Physics, Fluids & Plasmas
Shengji Wu, Bo Li, Zhigang Zuo, Shuhong Liu
Summary: This study systematically investigates the interaction between a laser-induced cavitation bubble and a free-settling spherical particle near a rigid boundary, identifying two important phenomena where the particle impacts on the boundary at high velocity. By combining numerical and analytical analyses with experiments, two limiting conditions of the particle-bubble bounce and particle-boundary impact are determined, providing guidance in controlling particle-bubble dynamics in practical applications.
PHYSICAL REVIEW FLUIDS
(2021)
Article
Engineering, Marine
Peng Chi, Zhang Shilong, Fu Jianhong, Li Qinfeng, Su Yu, Chang Hao, Chen Yuxuan, Yang Yun
Summary: This study investigates the feasibility of using a cavitation jet for drilling and stimulating shale gas reservoirs, and conducts erosion experiments on shale under different hydraulic conditions. The study finds that the optimal nozzle position increases linearly with upstream pressure, and a higher upstream pressure results in a greater erosion rate. The study also discusses the erosion mechanism and the impact of erosion time on reservoir permeability.
Article
Chemistry, Physical
K. Siemek, M. K. Eseev, P. Horodek, A. G. Kobets, I. Kuziv
Summary: The study on the defects evolution in nickel aluminum bronze CuAl9Ni4Fe4 subjected to cavitation under mild conditions for up to 8 hours revealed two different stages of cavitation erosion. The initial stage of up to 6 hours involved the removal of residual roughness and surface oxides, while in the maximal erosion rate region, large vacancy clusters were observed with a drastic increase in concentration compared to the incubation period.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Mechanical
Theresa Trummler, Steffen J. Schmidt, Nikolaus A. Adams
Summary: In this study, we numerically investigate the erosion potential of a cavitating liquid jet using high-resolution finite volume simulations. A barotropic equilibrium cavitation approach embedded into a homogeneous mixture model is employed as the thermodynamic model. The effects of collapsing vapor structures are resolved by considering full compressibility. Two different operating points with different cavitation intensities are analyzed, and their erosion potential is estimated and compared using various methods including collapse detection, maximum pressure distribution on the wall, and a new method of generating numerical pit equivalents. The data of numerical pit equivalents is analyzed in detail and compared with experimental data. Furthermore, a comprehensive grid study is presented for both operating points.
Article
Engineering, Mechanical
Jianhua Du, Fengjun Chen
Summary: The study reveals that the dynamics and pressure pulsation associated with cavitation erosion are closely related. A numerical model successfully predicts cavity evolution, volume, and pressure pulsation, demonstrating its reliability. The erosion pattern formed by cavitation is attributed to the distribution of pressure.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Mechanical
Mohammad Hossein Arabnejad, Urban Svennberg, Rickard E. Bensow
Summary: The paper proposes a numerical method based on energy description to assess the risk of cavitation erosion, with two improvements compared to other methods. Validation with experimental data shows good agreement between predicted high erosion risk areas and experimental erosion patterns. The method can also be used to study the relationship between cavity dynamics and cavitation erosion risk.
Article
Engineering, Mechanical
C. Y. Wang, W. Cheng, Y. K. Shao, K. Y. Luo, J. Z. Lu
Summary: The study found that laser shock peening treatment refined the original martensitic laths into fine equiaxed grains and induced compressive residual stresses in the surface layer. The increase in coverage layer significantly improved erosion resistance due to the grain refinement and compressive residual stresses induced by MLSPT.
Article
Engineering, Mechanical
Zhenhua Wang, Bing Zhang
Summary: The study reveals the initiation and propagation of cavitation erosion in super ferritic stainless steels. Cavitation erosion initiates at persistent slip bands and pits in grains with low Taylor factors, propagating along {100} planes and crossing grain boundaries below a certain angle. Grain boundaries with higher misorientation angles tend to retard the propagation of cavitation erosion.
Article
Mechanics
Ming-Kang Li, Shi-Ping Wang, Shuai Zhang, Hemant Sagar
Summary: This study experimentally investigates the complex interaction between underwater explosion (UNDEX) bubbles and a free surface. The dependence of the associated physics on the dimensionless detonation depth is revealed. Four typical bubble behavior patterns are identified and a critical value is found for ignoring the effects of the free surface on UNDEX bubbles. Good agreements are obtained with a unified theory for bubble dynamics. The dependence of pressure signals on the detonation depth is also investigated.
Article
Engineering, Mechanical
Kunpeng Su, Jianhua Wu, Dingkang Xia
Summary: The study explores the synergistic erosion between cavitation and solid particle erosion, revealing that suspension viscosity and particle size ratio are key parameters in predicting erosion. The model shows promise for erosion prediction and prevention by incorporating the opposing effects of microparticles in cavitation erosion.
Article
Thermodynamics
Manolia Andredaki, Konstantinos Vontas, Anastasios Georgoulas, Nicolas Miche, Marco Marengo
Summary: In this paper, the effect of the channel aspect ratio on bubble dynamics and heat transfer characteristics during the early transient stages of bubble growth in confined microchannels is studied using numerical simulations. The results show that the channel aspect ratio has a significant impact on bubble dynamics and heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Energy & Fuels
Jose Loyola-Fuentes, Luca Pietrasanta, Marco Marengo, Francesco Coletti
Summary: This study trains three classification algorithms using experimental data and selects the best algorithm based on their classification accuracy. The results show that the machine learning approach can reduce the uncertainty in flow pattern classification and improve flow regime predictions.
Article
Mechanics
D. J. Bouchard, M. Andredaki, A. Georgoulas, M. Marengo, S. Chandra
Summary: Experimentalists face limitations in deriving information from drop impact experiments on porous surfaces due to short timescales and the opaque nature of porous materials. Numerical simulations can provide additional information such as velocity and pressure profiles, as well as quantification of fluid volume flow rates into pores. Ethanol drops cleave at all tested conditions, while water drops only cleave at higher conditions. Numerical simulations reveal that the lower surface tension of ethanol leads to further spreading, less recoil, and less liquid above the gap, promoting cleaving.
Article
Thermodynamics
Andrzej I. Nowak, Luca Pietrasanta, Cezary Czajkowski, Marco Marengo, Slawomir Pietrowicz
Summary: Passive two-phase heat transfer systems, such as pulsating heat pipes, have promising thermal management applications in the space sector. This research investigates the effect of inertia on flow patterns to improve modeling tools for pulsating heat pipes operating under reduced gravity.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Ali Ahmed Alqahtani, Stuart Edwardson, Marco Marengo, Volfango Bertola
Summary: The heat transfer performance of a flat-plate, flexible polypropylene pulsating heat pipe (PHP) was experimentally evaluated. The bending angle and the reciprocal positions of the heat sink and source were found to have minimal effect on the thermal performance, but may affect the start-up of the PHP.
APPLIED THERMAL ENGINEERING
(2022)
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
Ning Qian, Fan Jiang, Marco Marengo, Jiajia Chen, Yucan Fu, Jingzhou Zhang, Jiuhua Xu
Summary: This study investigates the start-up behavior of oscillating heat pipes (OHP) under axial-rotation and highlights the importance of start-up speed on grinding efficiency and quality. It is found that OHP filled with acetone has the shortest start-up time, and the cold air pressure and centrifugal acceleration significantly affect the start-up time.
APPLIED THERMAL ENGINEERING
(2023)
Review
Thermodynamics
Marco Bernagozzi, Anastasios Georgoulas, Nicolas Miche, Marco Marengo
Summary: Electric vehicles are seen as a potential solution for reducing greenhouse gas emissions and addressing global warming. Battery thermal management is critical for the performance and sustainability of electric vehicles. Current technologies for battery thermal management in commercial vehicles include air and liquid cooling. This review focuses on the potential use of passive thermal devices called heat pipes for battery thermal management, analyzing different types of heat pipes and methods for removing excess heat. The review aims to collect research results, identify strengths and weaknesses, and propose future research directions for heat pipe battery thermal management systems.
APPLIED THERMAL ENGINEERING
(2023)
Review
Energy & Fuels
Phoevos (Foivos) Koukouvinis, John Anagnostopoulos
Summary: The expanding role of renewable energy sources, particularly hydropower, in the electricity market share is discussed in this review. The potential impact of hydropower on aquatic life, including lethality from various damage mechanisms, is examined. Experimental and numerical techniques for studying fish-friendly turbine designs are described, along with proposed holistic performance metrics for evaluating the fish-friendliness of hydropower installations. Recent developments and design practices for fish-friendly turbine concepts are presented.
Article
Mechanics
Sarvin Naji, Arvin Rahimi, Vahid Bazargan, Marco Marengo
Summary: In this study, a microfluidic chip using a non-embedded co-flow-focusing geometry was numerically simulated to improve droplet generation throughput. An artificial neural network model was trained to optimize the device geometry and flow rate, resulting in remarkable reduction of computation time. Additionally, a periodically switched laser simulation successfully predicted droplet generation frequency.
Article
Thermodynamics
Ning Qian, Fan Jiang, Marco Marengo, Yucan Fu, Jiuhua Xu
Summary: Grinding of difficult-to-machining materials generates excessive heat. Radial-rotating oscillating heat pipe (RR-OHP) can enhance heat transfer and control the temperature during grinding. Experimental results demonstrate that RR-OHP improves heat transfer efficiency in grinding process significantly.
APPLIED THERMAL ENGINEERING
(2023)
Article
Construction & Building Technology
Roberto Rugani, Marco Bernagozzi, Marco Picco, Giacomo Salvadori, Marco Marengo, Hui Zhang, Fabio Fantozzi
Summary: Personal Comfort Systems (PCSs) create localized comfort environments that satisfy individual needs and reduce energy consumption of main HVAC systems. A study focused on a new type of PCS - a warming desk - that uses conduction and radiation for efficient and effective heat transfer. Results showed that the warming desk provided good overall comfort and thermal sensation, with the ability to adjust the surface temperature for individual preferences. The PCS corrected the ambient temperature by about 7K, creating improved thermal comfort compared to centralized HVAC.
BUILDING AND ENVIRONMENT
(2023)
Article
Energy & Fuels
Konstantinos Vontas, Marco Pavarani, Nicolas Miche, Marco Marengo, Anastasios Georgoulas
Summary: This study investigates the applicability of the Eulerian-Eulerian two-fluid model and RPI model in non-conventional channels through numerical simulations. The model is validated and optimized using experimental data from conventional channels, and the importance of including a bubble coalescence and break-up sub-model is demonstrated.
Article
Materials Science, Multidisciplinary
Ghazal Biglari, Maedeh Saberi, Shervin Issakhani, Omid Jadidi, Jafar Farhadi, Vahid Bazargan, Marco Marengo
Summary: This study investigates the controllable patterning of bio-compatible polymers in the presence of a cross-linker in evaporating bi-dispersed colloidal drops. By changing the concentrations of sodium alginate and calcium chloride, the elemental distribution and deposition uniformity of the final patterns can be significantly altered.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Thermodynamics
Ning Qian, Yucan Fu, Jiajia Chen, Marco Marengo, Jingzhou Zhang, Jiuhua Xu
Summary: Oscillating heat pipes (OHP) have high heat transport capacity and simple structure, but research on their heat transfer performance under system rotation is insufficient. This study experimentally investigates the thermal performance of a centrifugal-accelerated single closed loop OHP and uses grey system theory to model the thermal performance and predict the heat transfer coefficient. The results show improved heat transfer characteristics with increased centrifugal acceleration, and the prediction model provides reliable guidance for engineering applications of OHPs.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Mechanics
Nicolas Bouvet, Savannah S. Wessies, Eric D. Link, Stephen A. Fink
Summary: This study presents a framework to characterize firebrand flows and compare exposure through the use of a measurement device and data processing methods. The ability to perform exposure comparisons and recognize combustion states is demonstrated.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
P. Botticini, G. Lavalle, D. Picchi, P. Poesio
Summary: This study investigates the gravity-driven liquid layer problem on an inclined plate, taking into account the variable density of the fluid. The study examines the influence of density variation on the formulation of a depth-averaged model and the role of compressibility in long-wave interfacial instability.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Jean-Paul Caltagirone
Summary: This article introduces a method for modeling capillary flows on a surface or at the interface of two fluids. The method involves handling the two components of capillary acceleration using the divergence and curl of surface normal. The proposed formulation is characterized by directional curvature based on dihedral angle, intrinsic anisotropic surface tension per unit mass, and introduction of capillary potential.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Qi-Teng Zheng, Chun-Bai-Xue Yang, Shi-Jin Feng, Yu-Chen Song, Yong Zhao, Yu-Lin Wu
Summary: This paper proposes a new two-phase partitioning boundary model to accurately predict the drying process of a porous medium from saturated to unsaturated conditions. The model is validated through laboratory soil drying tests and the study also investigates the effects of air-water interfacial area and water retention parameters on the drying process.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Alexandra Metallinou Log, Morten Hammer, Svend Tollak Munkejord
Summary: Flashing flow is commonly found in industrial systems and accurate flashing models are essential for the design of safe and efficient CO2 transportation systems. We propose a homogeneous flashing model that takes into account the physical phenomena of phase change. The model is fitted using CO2 pipe depressurization data and we find that the same model parameters can be applied for different cases.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Q. Tan, S. A. Hosseini, A. Seidel-Morgenstern, D. Thevenin, H. Lorenz
Summary: The possible impact of temperature differences during crystal growth is investigated in this study. A numerical model is developed to simulate the crystallization dynamics of (S)-mandelic acid, taking into account temperature effects. The study shows that the heat generation at the crystal interface has only a small effect on the surrounding temperature field.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Hideki Murakawa, Sana Maeda, Sven Eckert
Summary: This study investigates the behavior of bubbles in a liquid metal under the influence of a magnetic field, particularly bubble chains. The results show that increasing the magnetic field strength suppresses the oscillations of the bubbles and concentrates their crossing positions in a specific area. Applying these findings to numerical models can further optimize continuous casting processes.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Johanna Potyka, Kathrin Schulte
Summary: This paper presents an advanced Volume of Fluid (VOF) method for performing three-dimensional Direct Numerical Simulations (DNS) of the interaction of two immiscible fluids in a gaseous environment with large topology changes. The method includes efficient reconstruction of phase boundaries near the triple line using a Piecewise Linear Interface Calculation (PLIC) method and enhanced surface force modeling with the Continuous Surface Stress (CSS) model. Implementation of these methods in the multi-phase flow solver Free Surface 3D (FS3D) yielded successful validation. The simulations provide valuable insights into the collision process and can support future modeling of immiscible liquid interaction.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Martin Rohde, Sebastian Burgmann, Uwe Janoske
Summary: This study investigates the effect of superimposing an incident flow and two-dimensional vibration on the critical air flow velocity required for the detachment of a droplet. The results show that oscillatory excitation at specific frequencies can significantly reduce the critical velocity for droplet detachment.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Tea-Woo Kim, Baehyun Min
Summary: Liquid-gas two-phase slug flow is a complex flow pattern in energy systems, and accurately predicting slug liquid holdup is crucial for system design and operation. Existing HLLS models have limited applicability due to a lack of physical basis. This study proposes a new dimensionless number SP and correlates it with HLLS data, resulting in a unified HLLS correlation that agrees closely with experimental data.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Christian Lieber, Stephan Autenrieth, Kai-Yannic Schoenewolf, Amy Lebanoff, Rainer Koch, Sterling Smith, Paul Schlinger, Hans-Joerg Bauer
Summary: The observation of acoustically levitated droplets offers great potential for studying their evaporation characteristics. The main objective of this study is to present an experimental setup that minimizes the disturbing effects of the levitation technique in order to investigate convective heat and mass transfer during droplet evaporation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Facundo Cabrera-Booman, Nicolas Plihon, Mickael Bourgoin
Summary: The settling behavior of individual spheres in a quiescent fluid was experimentally studied. The mean trajectory angle with the vertical showed complex behavior as the parameters Gamma and Ga varied. The transition from planar to non-planar trajectories and the emergence of semi-helical trajectories were observed, especially for denser spheres.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Hongbin Wang, Hanwen Luo, Jinbiao Xiong
Summary: This article introduces an iterative screening method for closure models in nucleate boiling flow simulation, and demonstrates its accuracy through experiments.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Alexandra Metallinou Log, Morten Hammer, Han Deng, Anders Austegard, Armin Hafner, Svend Tollak Munkejord
Summary: This study investigates the rapid depressurization of liquid CO2 and compares the predictions of different models. It is found that higher temperatures result in shorter relaxation times.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)
Article
Mechanics
Rizwan Zahoor, Sasa Bajt, Bozidar Sarler
Summary: This numerical study evaluates the jet characteristics of non-Newtonian power-law fluids in a gas dynamic virtual nozzle. The results show that shear-thinning fluids result in thicker, longer, and slower jets compared to shear-thickening fluids. Additionally, a dripping-jetting phase diagram of the nozzle is obtained by varying the power law index, gas, and liquid flow rates.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2024)