International Journal of Multiphase Flow最新文献

英文中文

Effect of gas density on hydrodynamic characteristics and gas-liquid interfacial area in a 5 kW bubble column reactor

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-15 DOI: 10.1016/j.ijmultiphaseflow.2025.105220

Daewook Kim , Jae Jun Jang , Byung Wook Hwang , Hyungseok Nam , Doyeon Lee

This study investigated the impact of gas density on the hydrodynamic characteristics and gas-liquid interfacial area within a bubble column reactor, utilizing air, helium, and tap water. The performance of two types of distributors was compared. Key parameters such as gas holdup, transition gas holdup, transition velocity, bubble size, and specific interfacial area were analyzed across various gas velocities, pressures, and helium concentrations in the air-helium mixtures. As the gas density increased, the gas holdup, transition gas holdup, and transition velocity increased. The porous-plate distributor exhibited better performance metrics than the tube-type distributor. Furthermore, power-law relationships were derived for various parameters in both homogeneous and heterogeneous regimes. In the homogeneous regime, gas velocity exerted a more substantial influence on the gas holdup and specific interfacial area than gas density, whereas in the heterogeneous regime, both factors had nearly equivalent influences.

{"title":"Effect of gas density on hydrodynamic characteristics and gas-liquid interfacial area in a 5 kW bubble column reactor","authors":"Daewook Kim , Jae Jun Jang , Byung Wook Hwang , Hyungseok Nam , Doyeon Lee","doi":"10.1016/j.ijmultiphaseflow.2025.105220","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105220","url":null,"abstract":"<div><div>This study investigated the impact of gas density on the hydrodynamic characteristics and gas-liquid interfacial area within a bubble column reactor, utilizing air, helium, and tap water. The performance of two types of distributors was compared. Key parameters such as gas holdup, transition gas holdup, transition velocity, bubble size, and specific interfacial area were analyzed across various gas velocities, pressures, and helium concentrations in the air-helium mixtures. As the gas density increased, the gas holdup, transition gas holdup, and transition velocity increased. The porous-plate distributor exhibited better performance metrics than the tube-type distributor. Furthermore, power-law relationships were derived for various parameters in both homogeneous and heterogeneous regimes. In the homogeneous regime, gas velocity exerted a more substantial influence on the gas holdup and specific interfacial area than gas density, whereas in the heterogeneous regime, both factors had nearly equivalent influences.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105220"},"PeriodicalIF":3.6,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143642310","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}

引用次数: 0

Behavior of two-phase flow in a single pore with varying temperature and pressure

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-12 DOI: 10.1016/j.ijmultiphaseflow.2025.105202

K. Alex Chang

For a saturated compositional fluid flowing through a porous medium, a gas phase can appear and disappear. This phenomenon is affected by flow rate, pressure, and temperature. By analyzing a 2 × 2 dynamical system, a previous study investigated the relationship between the aforementioned phenomenon and the injected flow rate at fixed temperature and pressure. The present research extends that study by exploring this phenomenon at various temperatures, initial bubble sizes and outlet pressures. Our results indicate that the direction fields of the 2 × 2 dynamical system depend on the outlet pressure and temperature. At certain critical temperatures, the direction field develops singularity points. These critical temperatures depend on the outlet pressure and the injected concentration of CO

_{2}

; the critical temperatures increase as the outlet pressure increases and the critical temperatures decrease as the injected concentration of CO

_{2}

increases. For a fixed outlet pressure and injection flow rate, whether the gas phase behavior is steady-state or cyclic (unstable spiral state) depends on the ratio between inlet and outlet channel radii, as well as temperature. Our computations demonstrate that, at a fixed temperature, the gas phase transitions from a steady state to an unstable spiral state as the ratio of the inlet and outlet channel radii decreases. The steady state features of bubble size, gas phase pressure and liquid pressure depend on the temperature; the bubble size increases while the gas and liquid pressure decrease as the temperature increases.

{"title":"Behavior of two-phase flow in a single pore with varying temperature and pressure","authors":"K. Alex Chang","doi":"10.1016/j.ijmultiphaseflow.2025.105202","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105202","url":null,"abstract":"<div><div>For a saturated compositional fluid flowing through a porous medium, a gas phase can appear and disappear. This phenomenon is affected by flow rate, pressure, and temperature. By analyzing a 2 × 2 dynamical system, a previous study investigated the relationship between the aforementioned phenomenon and the injected flow rate at fixed temperature and pressure. The present research extends that study by exploring this phenomenon at various temperatures, initial bubble sizes and outlet pressures. Our results indicate that the direction fields of the 2 × 2 dynamical system depend on the outlet pressure and temperature. At certain critical temperatures, the direction field develops singularity points. These critical temperatures depend on the outlet pressure and the injected concentration of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>; the critical temperatures increase as the outlet pressure increases and the critical temperatures decrease as the injected concentration of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> increases. For a fixed outlet pressure and injection flow rate, whether the gas phase behavior is steady-state or cyclic (unstable spiral state) depends on the ratio between inlet and outlet channel radii, as well as temperature. Our computations demonstrate that, at a fixed temperature, the gas phase transitions from a steady state to an unstable spiral state as the ratio of the inlet and outlet channel radii decreases. The steady state features of bubble size, gas phase pressure and liquid pressure depend on the temperature; the bubble size increases while the gas and liquid pressure decrease as the temperature increases.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105202"},"PeriodicalIF":3.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628551","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}

引用次数: 0

Experimental and numerical study of microcavity filling regimes for Lab-on-a-Chip applications

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-11 DOI: 10.1016/j.ijmultiphaseflow.2025.105208

Luise Nagel , Anja Lippert , Ronny Leonhardt , Tobias Tolle , Huijie Zhang , Tomislav Marić

The efficient and voidless filling of microcavities is of great importance for Lab-on-a-Chip applications. However, predicting whether microcavities will be filled or not under different circumstances is still difficult due to the local flow effects dominated by surface tension. In this work, a close-up study of the microcavity filling process is presented, shedding light on the mechanisms of the filling process using experimental insights accompanied by 3D numerical simulations. The movement of a fluid interface over a microcavity array is investigated optically under consideration of different fluids, capillary numbers, and cavity depths, revealing a regime map of different filling states. Moreover, the transient interface progression over the cavities is analyzed with attention to small-scale effects such as pinning. Besides the visual analysis of the image series, quantitative data of the dynamic contact angle and the interface progression is derived using an automated evaluation workflow. In addition to the experiments, 3D Volume-of-Fluid simulations are employed to further investigate the interface shape. It is shown that the simulations can not only predict the filling states in most cases, but also the transient movement and shape of the interface. The data and code associated with this work are publicly available at Bosch Research GitHub (Bosch, 2024) and at the TUdatalib data repository (Nagel et al., 2024).

{"title":"Experimental and numerical study of microcavity filling regimes for Lab-on-a-Chip applications","authors":"Luise Nagel , Anja Lippert , Ronny Leonhardt , Tobias Tolle , Huijie Zhang , Tomislav Marić","doi":"10.1016/j.ijmultiphaseflow.2025.105208","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105208","url":null,"abstract":"<div><div>The efficient and voidless filling of microcavities is of great importance for Lab-on-a-Chip applications. However, predicting whether microcavities will be filled or not under different circumstances is still difficult due to the local flow effects dominated by surface tension. In this work, a close-up study of the microcavity filling process is presented, shedding light on the mechanisms of the filling process using experimental insights accompanied by 3D numerical simulations. The movement of a fluid interface over a microcavity array is investigated optically under consideration of different fluids, capillary numbers, and cavity depths, revealing a regime map of different filling states. Moreover, the transient interface progression over the cavities is analyzed with attention to small-scale effects such as pinning. Besides the visual analysis of the image series, quantitative data of the dynamic contact angle and the interface progression is derived using an automated evaluation workflow. In addition to the experiments, 3D Volume-of-Fluid simulations are employed to further investigate the interface shape. It is shown that the simulations can not only predict the filling states in most cases, but also the transient movement and shape of the interface. The data and code associated with this work are publicly available at Bosch Research GitHub (Bosch, 2024) and at the TUdatalib data repository (Nagel et al., 2024).</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105208"},"PeriodicalIF":3.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An immersed boundary method for particle-resolved simulations of arbitrary-shaped rigid particles

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-09 DOI: 10.1016/j.ijmultiphaseflow.2025.105200

Maximilian Schenk , Manuel García-Villalba , Jan Dušek , Markus Uhlmann , Manuel Moriche

The present work extends the direct-forcing immersed boundary method introduced by García-Villalba et al. (2023), broadening its application from spherical to arbitrarily-shaped particles, while maintaining its capacity to address both neutrally-buoyant and light objects (down to a density ratio of 0.5). The proposed method offers a significant advantage over existing methods regarding its simplicity, in particular for the case of neutrally-buoyant particles. Three test cases from the literature are selected for validation: a neutrally-buoyant prolate spheroid in a shear flow; a settling oblate spheroid; and, finally, a rising oblate spheroid.

引用次数: 0

Direct Numerical Simulation of collision events in flotation under the influence of gravity

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105204

Benedikt Tiedemann , Jochen Fröhlich

Collisions between particles and bubbles are decisive for the performance of flotation processes. In this work Direct Numerical Simulations of a prototypical gravitation-driven flotation process are presented with bubbles fully resolved and modelled as rigid spheres while the solid-phase is represented as point-particles. Key bubble and particle parameters correspond to realistic setups and are varied to study their effect on the collision rate. The study addresses the main influencing parameters, such as bubble diameter, gas hold-up, particle diameter, and particle density. Locally around the bubble significant differences of the collision behaviour exist. Most collisions occur on the upper bubble half, but some also on the lower bubble half. This is caused by a high particle-bubble relative velocity towards the bubble from the upper bubble half and an accumulation of particles at these locations as they deviate around the bubble. The paper provides reference data for flotation modelling.

引用次数: 0

Hollow droplet impact on a micro-trench hydrophilic surface

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105198

Lijuan Qian, Cheng Li, Chenlin Zhu

Hollow droplet impact on a solid surface occurs in applications ranging from controllable bio-medicine, thermal spray coating and additive manufacturing. In this work, we experimentally study the impact dynamics of silicone oil hollow droplets on a hydrophilic solid substrate, including a smooth surface and a micro-trench surface. The size of the total droplet and the air bubble are kept constant and we investigate the influence of the location of the air bubble, impact velocity, and micro-trench structure on the hollow droplet shape evolution. The results show that a counter-jet formed after the hollow droplet impact on a solid surface and the height of the counter-jet and the spreading diameter of the lamella grow with impact velocity. Two cavity break mode, natural crashing and external crashing, are found in our experiment and the critical Weber number

W e

is around 40. When

W e

reaches 70, the counter-jet clamps off and detaches from the surface. For a given hollow droplet, the spreading characteristics do not vary significantly with different locations of the air bubble, while the height of the central counter-jet increased with the increasing eccentricity. The effects of gap width and height of the micro-trench are discussed. The structured surfaces reduce the maximum spreading diameter compared to smooth surfaces. A theoretical model considering energy conversation is established to predict the maximum spreading diameter. The deviation between the predicted value and the measured value is less than 10%, which shows excellent consistency. These findings offer critical insights into the behavior of hollow droplets and hold significant potential for applications requiring precise droplet manipulation.

空心液滴撞击固体表面的应用范围很广，包括可控生物医学、热喷涂和增材制造。在这项工作中，我们通过实验研究了硅油空心液滴对亲水性固体基底（包括光滑表面和微沟槽表面）的冲击动力学。总液滴和气泡的大小保持不变，我们研究了气泡位置、冲击速度和微沟槽结构对空心液滴形状演变的影响。结果表明，空心液滴撞击固体表面后形成了反喷流，反喷流的高度和薄片的扩展直径随撞击速度的增加而增大。我们的实验发现了自然撞击和外部撞击两种破腔模式，临界韦伯数 We 约为 40。当韦伯数达到 70 时，反向射流会夹紧并脱离表面。对于给定的空心液滴，扩散特性随气泡位置的不同而变化不大，而中心反喷流的高度则随偏心率的增加而增加。讨论了微沟槽的间隙宽度和高度的影响。与光滑表面相比，结构化表面减小了最大扩散直径。建立了一个考虑能量对话的理论模型来预测最大扩张直径。预测值与测量值之间的偏差小于 10%，显示出极好的一致性。这些发现为空心液滴的行为提供了重要的见解，并为需要精确液滴操纵的应用提供了巨大的潜力。

{"title":"Hollow droplet impact on a micro-trench hydrophilic surface","authors":"Lijuan Qian, Cheng Li, Chenlin Zhu","doi":"10.1016/j.ijmultiphaseflow.2025.105198","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105198","url":null,"abstract":"<div><div>Hollow droplet impact on a solid surface occurs in applications ranging from controllable bio-medicine, thermal spray coating and additive manufacturing. In this work, we experimentally study the impact dynamics of silicone oil hollow droplets on a hydrophilic solid substrate, including a smooth surface and a micro-trench surface. The size of the total droplet and the air bubble are kept constant and we investigate the influence of the location of the air bubble, impact velocity, and micro-trench structure on the hollow droplet shape evolution. The results show that a counter-jet formed after the hollow droplet impact on a solid surface and the height of the counter-jet and the spreading diameter of the lamella grow with impact velocity. Two cavity break mode, natural crashing and external crashing, are found in our experiment and the critical Weber number <span><math><mrow><mi>W</mi><mi>e</mi></mrow></math></span> is around 40. When <span><math><mrow><mi>W</mi><mi>e</mi></mrow></math></span> reaches 70, the counter-jet clamps off and detaches from the surface. For a given hollow droplet, the spreading characteristics do not vary significantly with different locations of the air bubble, while the height of the central counter-jet increased with the increasing eccentricity. The effects of gap width and height of the micro-trench are discussed. The structured surfaces reduce the maximum spreading diameter compared to smooth surfaces. A theoretical model considering energy conversation is established to predict the maximum spreading diameter. The deviation between the predicted value and the measured value is less than 10%, which shows excellent consistency. These findings offer critical insights into the behavior of hollow droplets and hold significant potential for applications requiring precise droplet manipulation.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105198"},"PeriodicalIF":3.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609659","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}

引用次数: 0

Twin experiments for data assimilation of cavitating flow around a hydrofoil

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105201

Shungo Okamura, Kie Okabayashi

Twin experiments are conducted to clarify whether assimilation effects can be achieved by data assimilation (DA) with measurement data obtained by existing cavitation flow measurement techniques. The analysis object is the cavitation flow around a Clark-Y11.7% hydrofoil. The pseudo-measurement data are velocity fields from tomographic particle image velocimetry (TPIV) or two-dimensional PIV, both containing missing data in cavity, along with indirectly obtained cavity interface shapes. A large-eddy simulation is used for unsteady simulation of cavitating turbulent flow, and a local ensemble transform Kalman filter is used as the DA method. Visualized flow fields of the ensemble mean show that characteristic phenomena of the pseudo-measurement data are qualitatively reproduced. In addition, the time-series data at an observation point located at the position where the pseudo-measurement data exists converged following the pseudo-measurement data. The velocity inside the cavity, where no pseudo-measurement data exists, is also complemented by CFD that incorporates information from outside of the cavity. However, the complementation performance depends on the accuracy of the cavitation model. This DA program is applied to the real PIV data of single-phase flow and qualitatively reproduces the flow field. Furthermore, the observation noise is reduced and the data outside the measurement domain are complemented.

{"title":"Twin experiments for data assimilation of cavitating flow around a hydrofoil","authors":"Shungo Okamura, Kie Okabayashi","doi":"10.1016/j.ijmultiphaseflow.2025.105201","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105201","url":null,"abstract":"<div><div>Twin experiments are conducted to clarify whether assimilation effects can be achieved by data assimilation (DA) with measurement data obtained by existing cavitation flow measurement techniques. The analysis object is the cavitation flow around a Clark-Y11.7% hydrofoil. The pseudo-measurement data are velocity fields from tomographic particle image velocimetry (TPIV) or two-dimensional PIV, both containing missing data in cavity, along with indirectly obtained cavity interface shapes. A large-eddy simulation is used for unsteady simulation of cavitating turbulent flow, and a local ensemble transform Kalman filter is used as the DA method. Visualized flow fields of the ensemble mean show that characteristic phenomena of the pseudo-measurement data are qualitatively reproduced. In addition, the time-series data at an observation point located at the position where the pseudo-measurement data exists converged following the pseudo-measurement data. The velocity inside the cavity, where no pseudo-measurement data exists, is also complemented by CFD that incorporates information from outside of the cavity. However, the complementation performance depends on the accuracy of the cavitation model. This DA program is applied to the real PIV data of single-phase flow and qualitatively reproduces the flow field. Furthermore, the observation noise is reduced and the data outside the measurement domain are complemented.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105201"},"PeriodicalIF":3.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transient bubble rising in the presence of a surfactant at very low concentrations

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-08 DOI: 10.1016/j.ijmultiphaseflow.2025.105205

D. Fernández-Martínez , M.G. Cabezas , J.M. López-Herrera , M.A. Herrada , J.M. Montanero

We study the formation of the dynamic adsorption layer when a bubble is released in a tank containing water with a tiny amount of surfactant. The influence of the sorption kinetic constants is examined by comparing the experiments with Sodium Dodecyl Sulfate (SDS) and Triton X-100. The experiments allowed us to determine the parameter conditions that lead to a stable bubble rising and to validate the simulation. A simple scaling analysis and the simulation show that the formation of the dynamic adsorption layer can be split into three phases characterized by disparate time scales. The mechanisms controlling those phases are surfactant convection, adsorption–desorption, and diffusion. The amount of surfactant adsorbed onto the interface increases monotonously throughout the three phases. The experiments and the simulation show that the rising velocity reaches a maximum at times of the order of

k_{d}^{- 1}

(

k_{d}

is the desorption constant) when the dynamic adsorption layer is practically formed. This occurs even when only traces of surfactant are present in the liquid. The non-monotonous behavior of the maximum surfactant surface concentration is explained in terms of the reverse flow in the rear of the bubble right after the bubble release. This work contributes to the understanding of the complex interplay between hydrodynamics and surfactant transport and kinetics over bubble rising.

{"title":"Transient bubble rising in the presence of a surfactant at very low concentrations","authors":"D. Fernández-Martínez , M.G. Cabezas , J.M. López-Herrera , M.A. Herrada , J.M. Montanero","doi":"10.1016/j.ijmultiphaseflow.2025.105205","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105205","url":null,"abstract":"<div><div>We study the formation of the dynamic adsorption layer when a bubble is released in a tank containing water with a tiny amount of surfactant. The influence of the sorption kinetic constants is examined by comparing the experiments with Sodium Dodecyl Sulfate (SDS) and Triton X-100. The experiments allowed us to determine the parameter conditions that lead to a stable bubble rising and to validate the simulation. A simple scaling analysis and the simulation show that the formation of the dynamic adsorption layer can be split into three phases characterized by disparate time scales. The mechanisms controlling those phases are surfactant convection, adsorption–desorption, and diffusion. The amount of surfactant adsorbed onto the interface increases monotonously throughout the three phases. The experiments and the simulation show that the rising velocity reaches a maximum at times of the order of <span><math><msubsup><mrow><mi>k</mi></mrow><mrow><mi>d</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msubsup></math></span> (<span><math><msub><mrow><mi>k</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span> is the desorption constant) when the dynamic adsorption layer is practically formed. This occurs even when only traces of surfactant are present in the liquid. The non-monotonous behavior of the maximum surfactant surface concentration is explained in terms of the reverse flow in the rear of the bubble right after the bubble release. This work contributes to the understanding of the complex interplay between hydrodynamics and surfactant transport and kinetics over bubble rising.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105205"},"PeriodicalIF":3.6,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620170","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}

引用次数: 0

Exploring the influence of surface microstructures on cloud cavitation control: A numerical investigation

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-07 DOI: 10.1016/j.ijmultiphaseflow.2025.105206

Vahid Velayati , Khodayar Javadi , Bettar Ould-el-Moctar

This study explores the influence of surface microstructures, on controlling cloud cavitation dynamics over a three-dimensional Clark Y hydrofoil. The investigation focuses on the effects of rows of semi-spherical microstructures, strategically placed at three different locations on the hydrofoil's suction side. The study utilizes the Large Eddy Simulation (LES) approach to investigate the influence of these configurations on the cloud cavitation lifecycle, focusing on aspects such as cloud shedding frequency, hydrofoil efficiency, cavitation volume, and overall unsteadiness. The Reynolds number is considered to be

7 \times 10^{5}

and the angle of attack of the hydrofoil is fixed at 8 degrees. The results showed that placing the microstructures near the leading edge prolonged the sheet cavity and reduced the cloud cavitation shedding frequency by 5 %. However, this configuration also resulted in an 11.45 % decrease in the lift-to-drag ratio. Positioning semi-spherical microstructures along the mid-chord line resulted in a 4 % increase in cloud cavitation shedding frequency and a 5 % reduction in the lift-to-drag ratio. In contrast, implementing the semi-spherical surface microstructures near the trailing edge influenced the re-entrant jet and local pressure distribution, breaking large cavities into smaller ones. This naturally increased the frequency of cavity shedding by 19.4 % while also increasing the lift-to-drag ratio by approximately 2.5 %. The study also analyzes surface-vortex-cavitation interaction using the vorticity transport equation, finding that microstructures enhance vortex stretching while reducing vortex dilatation and baroclinic torque terms. Overall, the findings suggest that microstructures can stabilize cloud cavitation, leading to a more uniform pressure distribution and smoother flow over the hydrofoil.

{"title":"Exploring the influence of surface microstructures on cloud cavitation control: A numerical investigation","authors":"Vahid Velayati , Khodayar Javadi , Bettar Ould-el-Moctar","doi":"10.1016/j.ijmultiphaseflow.2025.105206","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105206","url":null,"abstract":"<div><div>This study explores the influence of surface microstructures, on controlling cloud cavitation dynamics over a three-dimensional Clark Y hydrofoil. The investigation focuses on the effects of rows of semi-spherical microstructures, strategically placed at three different locations on the hydrofoil's suction side. The study utilizes the Large Eddy Simulation (LES) approach to investigate the influence of these configurations on the cloud cavitation lifecycle, focusing on aspects such as cloud shedding frequency, hydrofoil efficiency, cavitation volume, and overall unsteadiness. The Reynolds number is considered to be <span><math><mrow><mn>7</mn><mspace></mspace><mo>×</mo><mspace></mspace><msup><mrow><mn>10</mn></mrow><mn>5</mn></msup><mspace></mspace></mrow></math></span>and the angle of attack of the hydrofoil is fixed at 8 degrees. The results showed that placing the microstructures near the leading edge prolonged the sheet cavity and reduced the cloud cavitation shedding frequency by 5 %. However, this configuration also resulted in an 11.45 % decrease in the lift-to-drag ratio. Positioning semi-spherical microstructures along the mid-chord line resulted in a 4 % increase in cloud cavitation shedding frequency and a 5 % reduction in the lift-to-drag ratio. In contrast, implementing the semi-spherical surface microstructures near the trailing edge influenced the re-entrant jet and local pressure distribution, breaking large cavities into smaller ones. This naturally increased the frequency of cavity shedding by 19.4 % while also increasing the lift-to-drag ratio by approximately 2.5 %. The study also analyzes surface-vortex-cavitation interaction using the vorticity transport equation, finding that microstructures enhance vortex stretching while reducing vortex dilatation and baroclinic torque terms. Overall, the findings suggest that microstructures can stabilize cloud cavitation, leading to a more uniform pressure distribution and smoother flow over the hydrofoil.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"188 ","pages":"Article 105206"},"PeriodicalIF":3.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620183","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}

引用次数: 0

Characterising slug flow in a horizontal pipe using bubble image velocimetry

IF 3.6 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-03-04 DOI: 10.1016/j.ijmultiphaseflow.2025.105196

Belma B. Hadzovic , Eirik Æsøy , Paul R. Leinan , James R. Dawson

In this paper, we investigate air–water slug flow in a horizontal pipe using bubble image velocimetry (BIV). We show that a good estimate of the ensemble-averaged velocity field can be obtained by tracking the bubbles using a correlation based method, even for highly aerated flows where traditional velocimetry methods such as particle image velocimetry (PIV) are very challenging to implement. The global slug statistics in terms of the translational velocity, slug frequency, and length are compared against measurements from gamma densitometers, showing excellent agreement for a wide range of operating conditions. New insight into the velocity variations of three distinct regions; the slug front, the slug body, and the liquid film, are identified and analysed using BIV. Furthermore, along with the velocity fields, the images were used to obtain an estimate of the bubble density spatial distribution to understand the bubble transport inside the liquid slugs.

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

International Journal of Multiphase Flow

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀