International Journal of Multiphase Flow最新文献

{"title":"Viscoplastic drops impacting a free-slip surface","authors":"Kindness Isukwem,&nbsp;Elie Hachem,&nbsp;Anselmo Pereira","doi":"10.1016/j.ijmultiphaseflow.2025.105177","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105177","url":null,"abstract":"<div><div>This theoretical and numerical study investigates the physical mechanisms that drive the spreading of viscoplastic drops of millimetric to centimetric size after they collide with a solid surface under free-slip conditions and negligible capillary effects. These impacting drops are modeled as Bingham fluids. The numerical simulations are conducted using a variational multi-scale method tailored to multiphase non-Newtonian fluid flows. The results are analyzed by examining the dynamics of spreading, energy balance, and scaling laws. The findings indicate that the kinetic energy from the impact of the drops is dissipated through viscoplastic effects during the spreading process, leading to the emergence of three distinct flow regimes: inertio-viscous, inertio-plastic, and mixed inertio-visco-plastic. These regimes are heavily influenced by the initial aspect ratio of the impacting drops, suggesting that morphology can be used to control spreading behavior. The study concludes with a diagram that correlates the drop’s maximum spreading and spreading time with various spreading regimes using a single dimensionless quantity termed the <em>impact parameter</em>.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"187 ","pages":"Article 105177"},"PeriodicalIF":3.6,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143454357","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":"Drag and interfacial vorticity of spherical bubble contaminated with soluble surfactant","authors":"Kosuke Hayashi ,&nbsp;Yuya Motoki ,&nbsp;Dominique Legendre ,&nbsp;Akio Tomiyama","doi":"10.1016/j.ijmultiphaseflow.2025.105173","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105173","url":null,"abstract":"<div><div>Numerical simulations of spherical bubbles contaminated with soluble surfactant were carried out to investigate the surfactant effects on the drag coefficient, <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span>, and the interfacial vorticity, <span><math><mi>ω</mi></math></span>, produced at the bubble interface. The different surface contamination regimes are considered in both the diffusion-dominant case and advection-dominant case, for different ambient contamination conditions controlled by varying the Marangoni, Langmuir and Hatta numbers, <span><math><mrow><mi>M</mi><mi>a</mi></mrow></math></span>, <span><math><mrow><mi>L</mi><mi>a</mi></mrow></math></span> and <span><math><mrow><mi>H</mi><mi>a</mi></mrow></math></span>. The combinations, <span><math><mrow><msub><mrow><mi>Π</mi></mrow><mrow><mi>M</mi></mrow></msub><mo>=</mo><mi>L</mi><mi>a</mi><mi>M</mi><mi>a</mi></mrow></math></span> and <span><math><mrow><msub><mrow><mi>Π</mi></mrow><mrow><mi>H</mi></mrow></msub><mo>=</mo><mi>H</mi><mi>a</mi><mo>/</mo><mi>L</mi><mi>a</mi></mrow></math></span>, of the dimensionless groups were found to play dominant roles in the surfactant effects on <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> and <span><math><mi>ω</mi></math></span> in both cases. Four different regimes for the dependence of the drag force and vorticity distribution as a function of the above dimensionless group were identified. In the diffusion-dominant case the vorticity is well correlated with a weighting average for those of clean and fully-contaminated bubbles, and a linear relation between <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> and the maximum vorticity holds as in the case with clean bubbles. The characteristics of <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> in the advection-dominant case are more complicated, but they have been classified into four regimes in terms of <span><math><msub><mrow><mi>Π</mi></mrow><mrow><mi>M</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>Π</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span>. A simple correlation of the stagnant-cap angle expressed in terms of <span><math><msub><mrow><mi>Π</mi></mrow><mrow><mi>M</mi></mrow></msub></math></span> was also obtained. This study thus revealed the surfactant effects on <span><math><msub><mrow><mi>C</mi></mrow><mrow><mi>D</mi></mrow></msub></math></span> and <span><math><mi>ω</mi></math></span> and the drag-vorticity relations in detail at the first time for the different regimes of surface contamination.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"187 ","pages":"Article 105173"},"PeriodicalIF":3.6,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445895","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}

{"title":"Lattice Boltzmann flux solver for immiscible three-phase fluids boiling with large density ratio and spontaneous nucleation","authors":"Da Zhang ,&nbsp;Yan Li","doi":"10.1016/j.ijmultiphaseflow.2025.105174","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105174","url":null,"abstract":"<div><div>In this study, we propose a three-phase boiling lattice Boltzmann flux solver (TB-LBFS) based on phase field theory. The TB-LBFS is capable of achieving spontaneous nucleation in nucleate boiling and handling multiphase flow calculations with large density ratios, such as 1:1000. The source terms in the control equations of TB-LBFS can be freely added and solved, offering high flexibility for secondary development. Additionally, TB-LBFS addresses the limitation of previous phase field boiling models that could not achieve spontaneous nucleation. The model's excellent capability in simulating three-phase flow phase transitions has been tested through multiple classic 2D and 3D cases, including 2D composite droplet evaporation, the 2D Leidenfrost phenomenon, and 3D nucleate boiling in both two-phase and three-phase systems.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"187 ","pages":"Article 105174"},"PeriodicalIF":3.6,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509158","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":"Large eddy simulations of free-falling perforated disks with small inertias","authors":"Wenhui Zhang,&nbsp;Yingjie Wei","doi":"10.1016/j.ijmultiphaseflow.2025.105154","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105154","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The dynamics of free-falling perforated disks of porosity &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;χ&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; are numerically investigated by the large eddy simulation (LES) within the range &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;100&lt;/mn&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mn&gt;1000&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;I&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∗&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Three falling styles are identified, namely spiral motion, spiral irregular motion and Hula-Hoop motion. A linear relationship of the Archimedes number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;A&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and the Reynolds number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; is observed within the intermediate Reynolds number regime. The mean values of crucial kinematic and dynamic variables are also given, and some scaling laws related to the perforated disk thickness &lt;span&gt;&lt;math&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; and diameter &lt;span&gt;&lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; are determined. For the mean descent velocity &lt;span&gt;&lt;math&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;z&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/math&gt;&lt;/span&gt;, the gravitational velocity &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;g&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; is a suitable characteristic velocity scale; this is not the case for the terminal velocity &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, which is proportional to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. The characteristic timescale &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; for vortex shedding is proportional to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, which indicates thin perforated disks facilitate vortex shedding. The mean normal force &lt;span&gt;&lt;math&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;F&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/math&gt;&lt;/span&gt; is proportional to &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;8&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mfrac&gt;&lt;mrow&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;/mrow&gt;&lt;/mfrac&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and irrespective of falling styles. It indicates different falling styles are","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105154"},"PeriodicalIF":3.6,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428818","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":"Critical elastic number for the elasto-inertial migration of spheroid in confined microchannel of viscoelastic fluids","authors":"Xiao Hu ,&nbsp;Jianzhong Lin ,&nbsp;Zhaosheng Yu ,&nbsp;Zhaowu Lin ,&nbsp;Yan Xia","doi":"10.1016/j.ijmultiphaseflow.2025.105178","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105178","url":null,"abstract":"<div><div>The critical elastic number for the elasto-inertial migration of spheroid in confined microchannel of viscoelastic fluid is numerically studied by the direct forcing/fictitious domain (DF/FD) method. The effect of the blockage ratio (<em>k</em>), aspect ratio (<em>α</em>), initial orientation and position of the particles, and the fluid elastic number (<em>El</em>) on the changes of equilibrium position and rotational behavior are explored, respectively. The results show that the confined microchannel reduce the number of rotational modes, prolate (oblate) spheroid exhibit four (three) kinds of rotational modes. The channel centreline (CC), diagonal line (DL) and cross-section midline (CSM) equilibrium positions are found within the present simulated parameters. For the first time, the prolate and oblate spheroid keeping the stable CC and DL equilibrium positions are simultaneously observed, but this phenomenon does not exist for spherical particles or small-sized spheroids. The strength of the particle induced-convection is a strong function of particle size, large particles are more susceptible to fluid inertia and migrate diagonally to the DL equilibrium position. Approaching the critical elastic number, particles can sudden change from the DL equilibrium position to the CC equilibrium position, the rotational modes are complex and depend on the fluid elastic number, the particle shape and size. The larger particles have the higher critical elastic number for equilibrium position transition than the small particles. Prolate spheroids have the smallest critical elastic number, then followed by sphere, the oblate spheroids require the highest elastic number to the CC equilibrium position.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105178"},"PeriodicalIF":3.6,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419787","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":"In-nozzle flow characteristics of superheated ethanol mixture","authors":"Xuhai Pan ,&nbsp;Yi Cao ,&nbsp;Wei Zhu ,&nbsp;Xueliang Zhu ,&nbsp;Xilin Wang ,&nbsp;Min Hua ,&nbsp;Juncheng Jiang","doi":"10.1016/j.ijmultiphaseflow.2025.105155","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105155","url":null,"abstract":"<div><div>Structural failure of storage tanks can result in the accidental release of superheated hazardous chemicals, causing catastrophic consequences. This study utilized a 20 L storage tank and a transparent nozzle to simulate the release process using pure water mixed with ethanol as the medium. The morphological characteristics of the two-phase flow of the flash jet, both inside and downstream of the nozzle, were analyzed using a capacitance sensor and high-speed imaging under storage temperatures (<em>T</em>_st = 110-150°C), storage pressures (<em>P</em>_st = 6-16 bar), and nozzle sizes (<em>D</em>= 1-6 mm). The results indicate that as the ethanol volume fraction increases, the physical properties of the superheated liquid-such as density and surface tension-decline, and the viscosity increases slightly. This reduces the energy required for gas nuclei within the nozzle to overcome surface tension forces. Consequently, smaller, denser bubbles are formed, leading to more intense jet fragmentation and atomization. Moreover, increasing superheat, storage pressure or nozzle size further amplifies bubble nucleation rates, jet radial expansion rates and break-up atomization, while significantly reducing droplet diameter. Finally, this study revises the void fraction criterion for the flash vaporization mechanism: external flashing (<em>α</em> = 0), internal flashing (0 &lt; <em>α</em> &lt; 23) and full flashing (<em>α</em> &gt; 23).</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105155"},"PeriodicalIF":3.6,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387044","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":"A probability model for predicting the bubble size distribution in slug flow in vertical pipes","authors":"Haixiao Liu,&nbsp;Jiawen Wang,&nbsp;Deping Sun","doi":"10.1016/j.ijmultiphaseflow.2025.105165","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105165","url":null,"abstract":"<div><div>In deep-sea mineral exploitation, slug flow shows promise for efficient mineral air-lifting but also poses risks of serious production safety accidents. Accurate prediction of the two-phase distribution in the liquid slug is crucial for efficient mineral lifting and accident prevention. This study develops a probability model for predicting the bubble size distribution of slug flow in vertical pipes. The liquid slug is divided into the near wake and far wake regions based on Taylor bubble wake influence. In the near wake, the vortex tears the liquid film at the tail of the Taylor bubble and generates new bubbles, while pushing the old bubbles to move towards the Taylor bubble, facilitating gas exchange between the Taylor bubble and the liquid slug. In the far wake region, vortices and random collisions enable dispersed bubbles to exchange gas with each other. These gas exchange processes occur continuously and maintain dynamic equilibrium in stable slug flow. Calculating the probability of the generation and death of a single bubble, along with the analysis of the bubble behavior, yields a probability model for predicting the bubble size distribution. The model is validated using experimental data and shows good consistency. The study investigated factors affecting the distribution of bubble size in slug flow, including gas phase velocity, liquid phase velocity, liquid density, liquid viscosity, and surface tension.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"187 ","pages":"Article 105165"},"PeriodicalIF":3.6,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438275","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":"Effects of Weber number and hole location on subcritical curtain flow regimes","authors":"Alessandro Della Pia","doi":"10.1016/j.ijmultiphaseflow.2025.105163","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105163","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The flow regimes of a gravitational plane liquid jet (curtain) issuing into a quiescent gaseous ambient are investigated in subcritical conditions, namely for inlet Weber number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. By means of three-dimensional direct numerical simulations based on the volume-of-fluid method, steady curtain base flow solutions are obtained and excited by introducing hole perturbations, whose evolution is assessed by variation of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; (i.e. the hole initial location) parameters. Depending on the combination of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, three different flow regimes are observed. In the sheet (S) regime, the hole perturbation expands in the curtain and is convected downstream, generating secondary holes washed out at the domain outflow, leaving the curtain intact. In the transient columns (TC) regime, the secondary holes expand and merge with the primary hole, generating vertical liquid ligaments (columns) expelled from the domain in finite time, leaving the curtain again in its original state. In the columns (C) regime, the curtain finally exhibits a transition from the continuous sheet shape to a discrete permanent (i.e. stationary) columns pattern. The phase diagram of the curtain flow is drawn by representing all numerical results in the parameters space &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;-&lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;. It is found that the S, TC and C regimes are clustered into three distinct regions of the diagram by two theoretical curves, namely &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;W&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, where &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;: for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the curtain is in the S regime; for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mi&gt;r&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the TC regime is obtained; for &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105163"},"PeriodicalIF":3.6,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369783","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":"Wall model for large eddy simulations accounting for particle effect","authors":"Ping Wang ,&nbsp;Zhizong Chen ,&nbsp;Nan Jin ,&nbsp;Xiaojing Zheng","doi":"10.1016/j.ijmultiphaseflow.2025.105152","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105152","url":null,"abstract":"<div><div>A new wall model is developed for the larger eddy simulation of particle-laden flow over erodible particle bed. To reasonably include particle-related physics in the model, we adopt the assumptions of conserved momentum flux and Prandtl mixing length for turbulent viscosity in the particle-laden flow. The model involves several empirical expressions, such as the non-dimensionlized particle mass flux, the mean particle saltating height and a correction coefficient that is <span><math><mrow><mo>∼</mo><mi>O</mi><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span>. The results of wall-resolved large eddy simulation with Lagrangian particle model are taken to be the “standard data” to test the performance of the proposed wall model. Several large eddy simulations without any wall model and with wall models developed for particle-free turbulence are also employed for comparison. The comparisons show that the proposed wall model provides much better predictions of particle statistics to the “standard data” than any other methods. The results of this study highlight the significance of incorporating additional particle effects in the wall model when performing large eddy simulations of particle-laden flow on a coarse grid.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105152"},"PeriodicalIF":3.6,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349997","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":"Study on cavity evolution of asynchronous parallel high-speed vertical water entry of cylinders","authors":"Yulin Wang 王玉琳,&nbsp;Yingjie Wei 魏英杰,&nbsp;Cong Wang 王聪","doi":"10.1016/j.ijmultiphaseflow.2025.105164","DOIUrl":"10.1016/j.ijmultiphaseflow.2025.105164","url":null,"abstract":"<div><div>This study conducted extensive experimental investigations on the asynchronous parallel high-speed vertical water entry of cylinders, examining the effects of varying lateral spacing, time intervals, and entry speeds. The research identified four distinct modes of cavity morphology for both the first and second cavities. For the first cavity, these modes include non-existent/destroyed, compressed, and quasi-single cavity, while the second cavity exhibits non-existent/destroyed, compressed, expanded, and quasi-single cavity forms. Multiple parameters were found to affect cavity morphology, with time interval emerging as a particularly crucial factor. The study revealed complex dynamics in cavity formation: the maximum diameter of the first cavity increases with increasing time intervals, while its maximum length exhibits a non-monotonic trend, initially decreasing and then increasing. The second cavity demonstrates even more intricate behavior, with its maximum diameter initially increasing, then decreasing with time intervals, followed by minor fluctuations. Its maximum length shows a pronounced non-monotonic trend, first decreasing, then increasing, followed by significant fluctuations. Notably, the position of the maximum diameter of the second cavity consistently aligns with the collapse plane of the first cavity. This study reveals complex dynamics in cavity interactions during parallel water entry based on the influence function <strong><em>φ</em></strong> defined. As the time interval increases, the impact of the second cavity on the first cavity progressively attenuates. Conversely, the influence of the first cavity on the second exhibits a non-monotonic trend: initially intensifying, then subsequently diminishing. The peak influence occurs when the time interval equals the ratio of the cylinder length to the water entry speed. Notably, when the time interval exceeds a critical threshold, defined as the ratio of the maximum length of a single cavity at the same speed to the water entry speed, the mutual influence between the first and second cavities becomes negligible. This analysis elucidates the intricate temporal dependencies in cavity formation and interaction during parallel high-speed water entries, providing valuable insights into the fluid dynamics of such phenomena.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"186 ","pages":"Article 105164"},"PeriodicalIF":3.6,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349854","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}