Pub Date : 2025-11-17DOI: 10.1016/j.ijmultiphaseflow.2025.105550
Jonas Görtz, Andreas Jupke
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.
{"title":"Exploring the bubble-electrolyte interplay in membrane electrolyzers: PIV measurement of electrolyte flow regimes","authors":"Jonas Görtz, 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}
Pub Date : 2025-11-17DOI: 10.1016/j.ijmultiphaseflow.2025.105548
Yicong Zhu, Yan Zhang, Ping Wang
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.
{"title":"Numerical study of particle rolling entrainment in wall turbulence on rough bed","authors":"Yicong Zhu, Yan Zhang, 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}
Pub Date : 2025-11-17DOI: 10.1016/j.ijmultiphaseflow.2025.105552
Semyon A. Zdornikov, Sergey V. Isaenkov, Andrey V. Cherdantsev
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.
{"title":"The effect of liquid properties on stratified-to-annular transition in a horizontal pipe","authors":"Semyon A. Zdornikov, Sergey V. Isaenkov, 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}
Pub Date : 2025-11-17DOI: 10.1016/j.ijmultiphaseflow.2025.105547
Michael Mansour , Mena Shenouda , Nicola Zanini , Dominique Thévenin
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.
{"title":"Eliminating gas accumulation in horizontal diverging channels under two-phase flow using upstream solid cross-flow steps","authors":"Michael Mansour , Mena Shenouda , Nicola Zanini , 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}
Pub Date : 2025-11-17DOI: 10.1016/j.ijmultiphaseflow.2025.105549
Liu Liu, Shiming Zhang, Gangliang Liu, Yu Qiu, Dongling Wu, Hongjie Yan
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 (), 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 () narrows. Correspondingly, the total drag force increases under stronger confinement. The instantaneous drag shows a clear dependence on both the Reynolds number () and the Eötvös number (), while the time-averaged drag correlates primarily with . Based on the experimental dataset, a predictive model for bubble aspect ratio as a function of 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 and the confinement ratio (), 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.
{"title":"Experimental study of single bubble rising behavior in an air–water system under parallel wall confinement","authors":"Liu Liu, Shiming Zhang, Gangliang Liu, Yu Qiu, Dongling Wu, 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}
Pub Date : 2025-11-15DOI: 10.1016/j.ijmultiphaseflow.2025.105543
Marc Vacher , Tullio Traverso , Christophe Josserand , Stéphane Perrard , Sophie Ramananarivo
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.
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.
{"title":"Shadowgraphy measurements of bubble jet coupled with surface oscillations","authors":"Marc Vacher , Tullio Traverso , Christophe Josserand , Stéphane Perrard , 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}
Pub Date : 2025-11-15DOI: 10.1016/j.ijmultiphaseflow.2025.105544
Ange Combrouze , Alexandra Klimenko , Nicolas Passade-Boupat , Pascal Panizza , François Lequeux , Laurence Talini , Emilie Verneuil
Foams may form in oil mixtures, such as lubricants, as a result of air entrainment. The long lifetimes of those foams significantly impair the thermal properties of lubricants and increase power losses by engines (Zhan et al., 2022). In order to improve the efficiency of lubricants, we offer here to gain insights in the stability of bubbles in binary mixtures of miscible oils as a function of bubble size and liquid composition. To do so, using a micro-millifluidic set-up, we control the formation of bubbles in oil mixtures and study variations in their coalescence time. The set-up allows to easily vary the curvature of the bubbles over one decade, perform statistics over a large number of coalescence events and measure coalescence times that span more than three orders of magnitude.
泡沫可能在油混合物中形成，如润滑油，由于空气夹带。这些泡沫的长寿命显著损害了润滑油的热性能，增加了发动机的功率损失（Zhan et al., 2022）。为了提高润滑油的效率，我们在这里提供了关于气泡大小和液体成分在混相油二元混合物中的稳定性的信息。为此，我们使用微微流体装置控制油混合物中气泡的形成，并研究其聚结时间的变化。该装置可以很容易地在十年内改变气泡的曲率，对大量的聚结事件进行统计，并测量超过三个数量级的聚结时间。
{"title":"High throughput measurement of bubble coalescence times using digital millifluidics","authors":"Ange Combrouze , Alexandra Klimenko , Nicolas Passade-Boupat , Pascal Panizza , François Lequeux , Laurence Talini , Emilie Verneuil","doi":"10.1016/j.ijmultiphaseflow.2025.105544","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105544","url":null,"abstract":"<div><div>Foams may form in oil mixtures, such as lubricants, as a result of air entrainment. The long lifetimes of those foams significantly impair the thermal properties of lubricants and increase power losses by engines (<span><span>Zhan et al., 2022</span></span>). In order to improve the efficiency of lubricants, we offer here to gain insights in the stability of bubbles in binary mixtures of miscible oils as a function of bubble size and liquid composition. To do so, using a micro-millifluidic set-up, we control the formation of bubbles in oil mixtures and study variations in their coalescence time. The set-up allows to easily vary the curvature of the bubbles over one decade, perform statistics over a large number of coalescence events and measure coalescence times that span more than three orders of magnitude.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105544"},"PeriodicalIF":3.8,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569377","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}
Pub Date : 2025-11-14DOI: 10.1016/j.ijmultiphaseflow.2025.105545
Ying Cai , Yunqiao Liu , Benlong Wang , Shu Takagi
Our study explores the effects of bubble–bubble interactions on plane sound wave propagation through spatially inhomogeneous and polydisperse bubbly liquids by extending the idea of bubble screen model (Pham et al., 2021). We introduce a decoupling approach to obtain the acoustic response of a bubble cloud, considering multiple interactions among bubbles. This approach consists of two key steps: firstly, the transformation of the randomly distributed bubble cloud into an organized system, and secondly, the decomposition of the interaction problem within the restructured system. Two distinct interaction mechanisms are identified, namely the intra-layer interactions and inter-layer interactions, corresponding to synchronous and asynchronous collective oscillations respectively. Based on the decoupling approach, we develop a modified effective medium model (MEMM) that demonstrates the different roles played by these interaction mechanisms and enables efficient predictions of acoustic propagation through bubble clouds with random spatial and size distributions. Using two-way coupled Eulerian–Lagrangian simulations, we validate the accuracy of this interaction decoupling for ordered bubble arrays, covering both linear and nonlinear regimes of bubble oscillations. Through discussions on spatial disorder and polydispersity, the applicability of this model is extended to more generalized bubble clouds with nonuniform distributions.
我们的研究通过扩展气泡屏模型的思想，探讨了气泡-气泡相互作用对平面声波在空间非均匀和多分散的气泡液体中传播的影响（Pham et al., 2021）。我们引入了一种解耦方法来获得气泡云的声学响应，考虑了气泡之间的多重相互作用。该方法包括两个关键步骤：首先，将随机分布的气泡云转化为有组织的系统，其次，分解重构系统内的交互问题。确定了两种不同的相互作用机制，即层内相互作用和层间相互作用，分别对应于同步和异步集体振荡。基于解耦方法，我们开发了一个改进的有效介质模型（MEMM），该模型展示了这些相互作用机制所起的不同作用，并能够有效预测具有随机空间和尺寸分布的气泡云中的声波传播。使用双向耦合欧拉-拉格朗日模拟，我们验证了这种相互耦耦对有序气泡阵列的准确性，涵盖了气泡振荡的线性和非线性区域。通过对空间无序性和多分散性的讨论，将该模型的适用性扩展到更广义的非均匀分布气泡云。
{"title":"Sound propagation through inhomogeneous and polydisperse bubble clouds: A decoupling approach","authors":"Ying Cai , Yunqiao Liu , Benlong Wang , Shu Takagi","doi":"10.1016/j.ijmultiphaseflow.2025.105545","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105545","url":null,"abstract":"<div><div>Our study explores the effects of bubble–bubble interactions on plane sound wave propagation through spatially inhomogeneous and polydisperse bubbly liquids by extending the idea of bubble screen model (Pham et al., 2021). We introduce a decoupling approach to obtain the acoustic response of a bubble cloud, considering multiple interactions among bubbles. This approach consists of two key steps: firstly, the transformation of the randomly distributed bubble cloud into an organized system, and secondly, the decomposition of the interaction problem within the restructured system. Two distinct interaction mechanisms are identified, namely the intra-layer interactions and inter-layer interactions, corresponding to synchronous and asynchronous collective oscillations respectively. Based on the decoupling approach, we develop a modified effective medium model (MEMM) that demonstrates the different roles played by these interaction mechanisms and enables efficient predictions of acoustic propagation through bubble clouds with random spatial and size distributions. Using two-way coupled Eulerian–Lagrangian simulations, we validate the accuracy of this interaction decoupling for ordered bubble arrays, covering both linear and nonlinear regimes of bubble oscillations. Through discussions on spatial disorder and polydispersity, the applicability of this model is extended to more generalized bubble clouds with nonuniform distributions.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105545"},"PeriodicalIF":3.8,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568896","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}
Pub Date : 2025-11-14DOI: 10.1016/j.ijmultiphaseflow.2025.105540
Masaya Saito, Ryuma Kojima, Shigeo Hosokawa
Film thickness distributions of the liquid films discharged from a rectangular nozzle with a high aspect ratio was successfully measured by using the adsorption of light due to the presence of fluorescence dye molecules solved in the liquid film. The measured results indicated that surface tension affects the liquid film thickness, especially in the edge region of the film flow, and that the acceleration of the film flow is higher than the gravitational acceleration.
{"title":"Film thickness measurement of film flow discharged from a rectangular nozzle with high aspect ratio","authors":"Masaya Saito, Ryuma Kojima, Shigeo Hosokawa","doi":"10.1016/j.ijmultiphaseflow.2025.105540","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105540","url":null,"abstract":"<div><div>Film thickness distributions of the liquid films discharged from a rectangular nozzle with a high aspect ratio was successfully measured by using the adsorption of light due to the presence of fluorescence dye molecules solved in the liquid film. The measured results indicated that surface tension affects the liquid film thickness, especially in the edge region of the film flow, and that the acceleration of the film flow is higher than the gravitational acceleration.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105540"},"PeriodicalIF":3.8,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569375","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}
Pub Date : 2025-11-13DOI: 10.1016/j.ijmultiphaseflow.2025.105542
Damien Fouquet, Julien Carmona, Vincent Moureau
This study proposes a Large-Eddy-Simulation framework for two-phase flows with heat transfer that is applied to a two-dimensional Liquid Jet in Cross-flow, a complex configuration with high deformation of the interface, where the framework behaves correctly and is in-line with the expected flow physics.
{"title":"Large-Eddy-Simulation framework for two-phase flows with heat transfer: Application to a two-dimensional jet in cross-flow","authors":"Damien Fouquet, Julien Carmona, Vincent Moureau","doi":"10.1016/j.ijmultiphaseflow.2025.105542","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105542","url":null,"abstract":"<div><div>This study proposes a Large-Eddy-Simulation framework for two-phase flows with heat transfer that is applied to a two-dimensional Liquid Jet in Cross-flow, a complex configuration with high deformation of the interface, where the framework behaves correctly and is in-line with the expected flow physics.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"195 ","pages":"Article 105542"},"PeriodicalIF":3.8,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517910","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}
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