International Journal of Multiphase Flow最新文献

{"title":"Comparative study of aerosol and hydrosol transport and deposition dynamics in turbulent wall-bounded flows","authors":"S. Abbasi,&nbsp;A. Mehdizadeh","doi":"10.1016/j.ijmultiphaseflow.2025.105551","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105551","url":null,"abstract":"<div><div>Understanding particle transport and deposition in wall-bounded turbulent flows is critical for numerous industrial and environmental applications. In this study, we investigate the dispersion and deposition dynamics of small aerosol and hydrosol particles in a turbulent channel flow at a friction Reynolds number of <span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>τ</mi></mrow></msub><mo>=</mo><mn>180</mn></mrow></math></span> using point-particle direct numerical simulations (PP–DNS). By decomposing the particle acceleration into drag, lift, pressure gradient, virtual mass, and Basset history components, we assess the relative influence of each acceleration across a range of particle sizes and density ratios (aerosol and hydrosol) in an upward flow motion, i.e. opposite direction of gravity. Our results show that while drag dominates the particle dynamics particularly for aerosols, lift becomes increasingly important with rising particle size. The Basset history, pressure gradient and virtual mass accelerations have only a negligible contribution to the total acceleration. Regarding hydrosol, pressure gradient has a constant contribution to particle acceleration, largely independent of particle size, where the effect of virtual mass decreases with the increase of particle size. On the other hand, Basset history acceleration, shows size-dependent behavior. For small particles, the Basset history acceleration contributes to the particle acceleration with a magnitude comparable to the pressure gradient. As the particle size increases, this contribution decreases, and its dynamics changes once the hydrosol particle size approaches the Kolmogorov scale. Additionally, both pressure gradient and Basset history have significant input on deposition for hydrosol particles comparable to Kolmogorov length scale.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105551"},"PeriodicalIF":3.8,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlling Taylor bubble migration in a non-concentric annulus: full-scale experiments applied to well drilling operations","authors":"Eric R. Upchurch ,&nbsp;Yaxin Liu ,&nbsp;Evren M. Ozbayoglu","doi":"10.1016/j.ijmultiphaseflow.2025.105553","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105553","url":null,"abstract":"<div><div>An experimental investigation into Taylor bubble countercurrent behavior in an eccentric 0.1524 m x 0.1016 m (6 in. x 4 in.) annulus using non-Newtonian fluids is presented. This annulus configuration and the fluids tested are commonly used in oil, gas and geothermal drilling operations, but are not reflected in the existing research literature. Fluid rheology, annulus inclination, and internal pipe rotational speed are varied to provide an understanding of Taylor bubble physics under countercurrent flow and its implications for effectively managing unwanted upward gas migration that can occur in a wellbore during drilling operations in fractured or vugular rock formations.</div><div>Water and Bingham plastic fluids of ever-increasing plastic viscosity (<em>μ_p</em>) and yield point (<em>τ_y</em>) are tested to determine the minimum average downward fluid velocity (i.e., <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span>) that each requires to halt Taylor bubble migration. Increases in <em>μ_p</em> and <em>τ_y</em> do not monotonically reduce <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span>. Instead, moderate increases up to <em>μ_p</em> = 31 cP and <em>τ_y</em> = 40 lb/100 ft² increase <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span> – while further increases in <em>μ_p</em> and <em>τ_y</em> reduce <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span>, but at the cost of increased friction pressures in the wellbore. Accepting a larger <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span> reduces friction pressures but requires using larger fluid volumes during the drilling process. Conversely, minimizing <span><math><msub><mover><mrow><mi>V</mi></mrow><mo>‾</mo></mover><mi>min</mi></msub></math></span> induces higher friction pressure on the wellbore. Determining the appropriate balance of these factors, and others, when planning drilling operations requires integrating the findings of our low-pressure experiments with that of recently published high-pressure Taylor bubble migration experiments. A discussion of the various considerations in such planning is presented.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105553"},"PeriodicalIF":3.8,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145615311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular dynamics study of boiling on the surface of hybrid wettability rectangular cavity nanostructures","authors":"Dongling Liu,&nbsp;Xiaoping Luo,&nbsp;Yijie Fan,&nbsp;Jinxin Zhang","doi":"10.1016/j.ijmultiphaseflow.2025.105555","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105555","url":null,"abstract":"<div><div>This study explores the influence of rectangular cavity wettability and size on explosive boiling through nonequilibrium molecular dynamics (MD) simulations. Hybrid wettability rectangular cavity nanostructured surfaces (HWRN) were constructed. Among them, surfaces HWRN-A1 to HWRN-A6 represent a gradual decrease in cavity wettability, while surfaces HWRN-B1 to HWRN-B6 correspond to a gradual increase in the area ratio of the superhydrophobic cavity surface. The atomic energy distribution of the argon liquid film was analyzed to investigate the mechanism of surface wettability on bubble nucleation. The heated surface temperature increased from 90 K to 180 K in 15 ns (6K/ns). The simulation results indicate that reducing the wettability of the rectangular cavities on the HWRN-A surface shortens the time for both bubble nucleation and explosive boiling. The explosive boiling time of HWRN-A6 (superhydrophobic cavity) is 225 ps earlier than that of HWRN-A1 (superhydrophilic cavity). The bubble nucleation time demonstrates a decreasing then increasing trend with the expansion of HWRN-B's cavity area. Under the conditions of this study, the optimal area ratio of HWRN-B was 8% (B3). The surfaces with the largest CHF in the HWRN-A and HWRN-B groups of studies were HWRN-A6 (5.4 × 10^–4eV/(nm²·ps)) and HWRN-B3 (5.7 × 10^–4 eV/(nm²·ps)), respectively.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105555"},"PeriodicalIF":3.8,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145615310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical modeling of coalescence of two equal-sized droplets coated with particles","authors":"Hanlin Zhou ,&nbsp;Ningjing Mao ,&nbsp;Yong Liu ,&nbsp;Hong Liang ,&nbsp;Haihu Liu","doi":"10.1016/j.ijmultiphaseflow.2025.105554","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105554","url":null,"abstract":"<div><div>Coalescence dynamics of two equal-sized droplets coated with a fixed number of particles is numerically investigated using the lattice Boltzmann color-gradient model coupled with particle dynamics. By varying particle distribution range, we first show that the addition of particles can retard droplet deformation, and even in the absence of particles in the growth region of liquid bridge, more particles distributed at the axial ends of droplets significantly hinder droplet deformation. This is mainly because high kinetic energy region, which is concentrated at the axial ends of the droplet, is inhibited by particles in this region. We then vary the viscosity ratio of ambient fluid to droplet and find that for a moderate viscosity ratio, decreasing the particle distribution range causes the droplet oscillation mode to shift from critically damped to overdamped. In the under-damped mode, droplets are able to reach steady state earlier with a decrease in particle distribution range, while an opposite trend is observed in the overdamped mode. We also demonstrate that in addition to introducing particles, the reduction of particle distribution range equally contributes to increasing apparent viscosity of the ambient fluid. Finally, it is found that as the contact angle decreases, the damping ratio of droplet oscillations increases due to increased viscous dissipations and thus the maximum kinetic energy that the droplet can achieve decreases. As the particle distribution range increases, the effect of particles on droplet oscillations weakens, gradually making total kinetic energy and droplet deformation evolution curves for different contact angles indistinguishable.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105554"},"PeriodicalIF":3.8,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the bubble-electrolyte interplay in membrane electrolyzers: PIV measurement of electrolyte flow regimes","authors":"Jonas Görtz,&nbsp;Andreas Jupke","doi":"10.1016/j.ijmultiphaseflow.2025.105550","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105550","url":null,"abstract":"<div><div>Gas-evolving electrochemical processes, such as water-splitting, are heavily affected by the presence of gas bubbles. Detached electrogenerated bubbles alter electrolyte conductivity, and attached bubbles reduce the active electrode surface area. However, due to the complex interaction between gas bubbles and electrolyte flow, estimating gas phase fractions and flow patterns within membrane-separated parallel plate electrolyzers is challenging. Utilizing a partially transparent electrolyzer equipped with a 5k high-speed camera, this work applies particle image velocimetry (PIV) to capture time-averaged detailed flow fields across different current densities, superficial electrolyte velocities, heights, and electrode-membrane gaps. The findings reveal distinct flow regimes transforming from quasi-steady segregated flows under no net flow conditions into pseudo-turbulent flows with increased forced convection. Moreover, variations in current density, superficial electrolyte velocity, and electrode-membrane gap are shown to critically define the upward flow regime’s width and turbulence levels. Out of all studied parameters, we found the superficial electrolyte velocity to be the predominant factor for the width of the bubble curtain. The presented findings support understanding bubble-electrolyte interactions, flow patterns, and gas phase distribution in parallel-plate electrolyzers.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105550"},"PeriodicalIF":3.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical study of particle rolling entrainment in wall turbulence on rough bed","authors":"Yicong Zhu,&nbsp;Yan Zhang,&nbsp;Ping Wang","doi":"10.1016/j.ijmultiphaseflow.2025.105548","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105548","url":null,"abstract":"<div><div>The transport of sediment particles in turbulent flow is widespread in nature. The entrainment of bed particle represents the first step in forming and developing multiphase flow. According to the observed fact that the duration of fluid force acting on the particles is equally significant as its magnitude, event-based entrainment criterions have been developed to analyze the dynamical interactions between the particles and turbulence. However, these models, mainly based on wind tunnel or water channel experiments, only focus on the fluid forces and particle motions in two-dimensional plane (streamwise and vertical). Recent studies highlight the importance of spanwise fluid action, which depends on particle bed arrangement. In this work, the semi-resolved particle Lagrangian tracking method and direct numerical simulation of wall turbulence four-way coupled with particles are employed to simulate the rolling entrainment of individual particles for different bed arrangement and various Shields numbers. The simulation results illustrate that on specific bed arrangement, the spanwise fluid effect cannot be neglected and will lead to none-streamwise rolling entrainment. The fluid structures surrounding the particles during the entrainment process were analyzed, revealing that at lower Shields numbers, sweep events are the primary driving force for particle entrainment. Furthermore, for particles initiating motion in the spanwise direction, the conditional surrounding spanwise velocity field is asymmetrical and the spanwise structures are according the direction of motion. After simplifying the complex three-dimensional force/torque analysis by a projection method, a three-dimensional impulse criterion for particle entrainment was developed and validated by the numerical simulation results.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"196 ","pages":"Article 105548"},"PeriodicalIF":3.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145610440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of liquid properties on stratified-to-annular transition in a horizontal pipe","authors":"Semyon A. Zdornikov,&nbsp;Sergey V. Isaenkov,&nbsp;Andrey V. Cherdantsev","doi":"10.1016/j.ijmultiphaseflow.2025.105552","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105552","url":null,"abstract":"<div><div>Under low liquid loading, gas-liquid flow in a horizontal pipe has two main flow patterns: stratified and annular flows, which have significantly different integral characteristics such as pressure drop and heat transfer rate. Here we investigate transition between these flow patterns in a horizontal 20 mm pipe using working liquids with different viscosity and surface tension. Backlit visualization with background images is employed to distinguish the flow patterns and measure the height of liquid lifting. Brightness-Based Laser-Induced Fluorescence technique is used to measure film thickness and investigate spatiotemporal evolution of waves on film surface. Several unexpected observations were made. For large gas speeds, both reduced surface tension and increased viscosity facilitate upward climbing of thin liquid film and transition to annular flow. Circumferential spreading of disturbance waves is not directly related to the climbing of thin liquid film, and often shows opposite tendencies regarding the change in liquid properties. Transition to annular flow may occur in absence of disturbance waves, which confirms secondary role of large waves in liquid lifting. The liquid with low surface tension behaves as if it was more viscous, which might be related to intensive entrapment of gas bubbles by the liquid film.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105552"},"PeriodicalIF":3.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eliminating gas accumulation in horizontal diverging channels under two-phase flow using upstream solid cross-flow steps","authors":"Michael Mansour ,&nbsp;Mena Shenouda ,&nbsp;Nicola Zanini ,&nbsp;Dominique Thévenin","doi":"10.1016/j.ijmultiphaseflow.2025.105547","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105547","url":null,"abstract":"<div><div>Gas accumulation in gas–liquid two-phase flows creates major challenges in centrifugal pumps and diverging channels, as trapped gas in low-pressure separation zones promotes flow separation, reduces pressure recovery, and increases the risk of system failure. To address this, the present study proposes a novel and simple passive control strategy using upstream cross-flow solid steps of varying heights (2, 5, and 8 mm) in a horizontal diverging channel. Controlled experiments combining Laser Doppler Anemometry (LDA), high-speed imaging, and pressure measurements were performed to evaluate the effect of step height on flow separation, bubble behavior, and pressure recovery. Results show that steps of 5 mm and 8 mm could successfully eliminate gas accumulation and significantly improve pressure recovery compared to the baseline without steps, while the 2 mm step had only a marginal effect. These improvements are attributed to enhanced bubble breakup, increased vertical dispersion, and elevated turbulence, while reducing flow separation. The findings not only provide benchmark data for validating two-phase flow models but also offer practical design guidelines for improving gas handling in centrifugal pumps and related industrial systems.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105547"},"PeriodicalIF":3.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of single bubble rising behavior in an air–water system under parallel wall confinement","authors":"Liu Liu,&nbsp;Shiming Zhang,&nbsp;Gangliang Liu,&nbsp;Yu Qiu,&nbsp;Dongling Wu,&nbsp;Hongjie Yan","doi":"10.1016/j.ijmultiphaseflow.2025.105549","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105549","url":null,"abstract":"<div><div>The effect of parallel-wall confinement on single bubble rising dynamics was systematically investigated using the shadowgraph technique. Experiments were performed in rectangular channels under varying degrees of lateral confinement to examine the evolution of bubble aspect ratio, terminal velocity, and drag force. Results reveal that confinement increases the average bubble aspect ratio, which exhibits a strong dependence on the Weber number (<span><math><mrow><mi>W</mi><mi>e</mi></mrow></math></span>), indicating that bubble deformation is primarily governed by the interplay between inertial and surface tension forces. Terminal velocity decreases significantly with increasing confinement, and for bubbles of equal volume, velocity drops monotonically as the wall spacing (<span><math><mrow><mi>G</mi><mi>A</mi><mi>P</mi></mrow></math></span>) narrows. Correspondingly, the total drag force increases under stronger confinement. The instantaneous drag shows a clear dependence on both the Reynolds number (<span><math><mrow><mi>R</mi><mi>e</mi></mrow></math></span>) and the Eötvös number (<span><math><mrow><mi>E</mi><mi>o</mi></mrow></math></span>), while the time-averaged drag correlates primarily with <span><math><mrow><mi>E</mi><mi>o</mi></mrow></math></span>. Based on the experimental dataset, a predictive model for bubble aspect ratio as a function of <span><math><mrow><mi>W</mi><mi>e</mi></mrow></math></span> is proposed, which outperforms existing models in terms of generality across a wide range of confinement levels. Furthermore, by introducing a wall-effect correction factor that accounts for <span><math><mrow><mi>E</mi><mi>o</mi></mrow></math></span> and the confinement ratio (<span><math><mi>s</mi></math></span>), the proposed terminal velocity model achieves a mean relative error of 6.70%, significantly enhancing its predictive accuracy. Finally, a unified drag force model applicable to both confined and unconfined regimes is developed, offering improved scalability and robustness for engineering applications.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105549"},"PeriodicalIF":3.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shadowgraphy measurements of bubble jet coupled with surface oscillations","authors":"Marc Vacher ,&nbsp;Tullio Traverso ,&nbsp;Christophe Josserand ,&nbsp;Stéphane Perrard ,&nbsp;Sophie Ramananarivo","doi":"10.1016/j.ijmultiphaseflow.2025.105543","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105543","url":null,"abstract":"<div><div>We present an image processing method to track and characterize the motion of air–liquid interfaces occurring in aerated liquid baths. In a rectangular tank filled with water, an immersed sparger injects air vertically at a constant flow rate and creates well-defined sloshing oscillations of the free surface. The phenomenon is referred to as self-induced sloshing.</div><div>We retrieve the positions of both the surface and the jet position using a tailored image processing method based on shadowgraphy. Using Complex Orthogonal Decomposition (COD), we reveal the main spatial and temporal dynamics of the oscillations.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105543"},"PeriodicalIF":3.8,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}