International Journal of Multiphase Flow最新文献

{"title":"Effects of initial ellipsoidal geometry on droplet deformation and unsteady drag in the bag-breakup regime","authors":"Hongyu Ju,&nbsp;Yue Li,&nbsp;Hongxia Liang,&nbsp;Longxi Zheng,&nbsp;Jianqin Suo","doi":"10.1016/j.ijmultiphaseflow.2026.105847","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105847","url":null,"abstract":"<div><div>The transient deformation of droplets in gas flows is strongly affected by the initial droplet geometry, whereas most previous studies have focused on initially spherical droplets. In this study, large-eddy simulation (LES) coupled with the volume-of-fluid (VOF) method was used to investigate the deformation of initially prolate spheroidal, i.e., ellipsoidal, droplets in the bag-breakup regime, with initial aspect ratios ranging from 1 to 5 and inclination angles ranging from 0° to 90°. The results show that ellipsoidal droplets generally follow a deformation sequence similar to that of spherical droplets, evolving from a disk-like structure toward a bag-like configuration, while the detailed morphology, breakup timing, and breakup mode remain strongly dependent on the initial geometry. A unified piecewise correlation is developed for the evolution of the equivalent windward-face diameter and is found to describe both spherical and ellipsoidal cases reasonably well over the present parameter range. Increasing the initial aspect ratio suppresses the growth of the equivalent windward-face diameter, whereas decreasing the inclination angle enhances it and may promote a transition from bag breakup to bag–stamen breakup. The initial geometry also alters the wake structure and pressure distribution, thereby affecting the unsteady drag response: larger aspect ratios tend to reduce the peak drag level, whereas the inclination angle mainly affects the early drag oscillation through wake asymmetry. Overall, these findings clarify the role of initial nonspherical geometry in droplet deformation and aerodynamic response under bag-breakup conditions, and provide a physical basis for future modeling of droplets with non-spherical initial shapes.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"202 ","pages":"Article 105847"},"PeriodicalIF":3.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148641591","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":"Impact of unconventional propeller geometries on tip vortex cavitation noise: A numerical study","authors":"Adrian Portillo-Juan,&nbsp;Simone Saettone,&nbsp;Esteban Ferrer","doi":"10.1016/j.ijmultiphaseflow.2026.105843","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105843","url":null,"abstract":"<div><div>Underwater radiated noise generated by marine propellers has become a major environmental concern, particularly in ecologically sensitive regions such as the Mediterranean Sea. Among the different cavitation regimes, tip vortex cavitation is one of the most persistent and dominant noise sources, often requiring unconventional blade geometries for effective mitigation. This study investigates the influence of tip-raked and toroidal propeller geometries on tip vortex cavitation dynamics and the associated hydroacoustic response. Three propeller configurations were analyzed numerically under cavitating operating conditions using a RANS–DES framework coupled with a VOF cavitation model and a permeable Ffowcs Williams–Hawkings acoustic analogy. The investigated geometries include a conventional baseline propeller, a pressure-side-oriented tip-raked configuration, and a toroidal design derived from the baseline geometry. Results show that both unconventional geometries reduce sound pressure levels by up to 20 dB (ref = 1 <span><math><mi>μ</mi></math></span>Pa) within the 150 Hz–6 kHz range without significant hydrodynamic efficiency losses. The tip-raked propeller suppresses the primary tip vortex and weakens secondary vortex interactions, reducing broadband acoustic emissions. Furthermore, the toroidal configuration completely suppresses coherent tip-vortex cavitation structures and produces the most stable acoustic response among the analyzed cases. Overall, the results demonstrate that unconventional blade-tip geometries can substantially mitigate cavitation-induced noise while preserving propulsive performance, supporting their potential as environmentally sustainable marine propulsion solutions.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"202 ","pages":"Article 105843"},"PeriodicalIF":3.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148641592","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":"Experimental investigation of injection orientation on liquid jet dynamics in supersonic crossflow","authors":"Srinivas M.V.V.,&nbsp;Arun Kumar Rajagopal","doi":"10.1016/j.ijmultiphaseflow.2026.105849","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105849","url":null,"abstract":"<div><div>The present study examines the effect of injector orientation on liquid jet breakup, shock structures, and the associated flow interactions for liquid injection into a Mach 2.1 supersonic crossflow. Three injector configurations with injection angles of 135°, 90°, and 45°are considered. The breakup of the liquid jet analyzed using back-lit imaging show that for the 135° counterflow injection, the liquid jet breaks up very close to the injector exit due to the strong aerodynamic forces imposed by the opposing supersonic crossflow. In contrast, the 45° injection case shows very little breakup because the aerodynamic loading on the liquid column is relatively weaker. The shock structures for different injection cases are studied using shadowgraph imaging over a range of momentum flux ratios (<span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>l</mi></mrow></msub></math></span>). The 135° injection produces a stronger bow shock and further, the interaction of the bow shock with the top wall transitions from regular reflection to Mach reflection at lower <span><math><msub><mrow><mi>J</mi></mrow><mrow><mi>l</mi></mrow></msub></math></span> values compared to other injection cases. The stronger bow shock also leads to a larger upstream separation region and increased liquid entrainment. Dynamic Mode Decomposition further identifies coherent structures governing the jet dynamics, with dominant frequencies matching those obtained from jet interface oscillations and bow shock motion.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"202 ","pages":"Article 105849"},"PeriodicalIF":3.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148642055","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":"Corrigendum to “Influence of dissolved gas concentration on the lifetime of surface bubbles in volatile liquids” [Int. J. Multiph. Flow 196 (2026) 105580]","authors":"Xin Li,&nbsp;Yanshen Li","doi":"10.1016/j.ijmultiphaseflow.2026.105845","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105845","url":null,"abstract":"","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"202 ","pages":"Article 105845"},"PeriodicalIF":3.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148642056","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":"Corrigendum to IJMF Article 105740","authors":"T. Daoud,&nbsp;T.L. Jackson,&nbsp;S. Balachandar","doi":"10.1016/j.ijmultiphaseflow.2026.105804","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105804","url":null,"abstract":"","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"202 ","pages":"Article 105804"},"PeriodicalIF":3.9,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148641593","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":"Impact of water droplet on oil films suspended over water bath: Crater and jet dynamics","authors":"Xiaolong He ,&nbsp;Qian Yang ,&nbsp;Haonan Peng ,&nbsp;Linlin Fei ,&nbsp;Jianmin Zhang ,&nbsp;Ya-Ling He","doi":"10.1016/j.ijmultiphaseflow.2026.105644","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105644","url":null,"abstract":"<div><div>The water droplet impact dynamics on an oil film over the water bath are studied based on extensive experiments, with a focus on the effects of key parameters (droplet size, impact velocity, and oil-film thickness) on the crater growth and the jet formation. A multi-interfaces theory, considering the surface-energy variations of the deformed droplet–air, oil–droplet, and oil–water interfaces, is proposed to describe the total change in the surface energy during the impact, leading to an effective surface tension and Weber number for the following analysis. The maximum crater depth follows a scaling <span><math><mrow><msubsup><mi>d</mi><mi>e</mi><mo>′</mo></msubsup><mo>∼</mo><mrow><mo>(</mo><mrow><mi>F</mi><msup><mrow><mi>r</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>4</mn></mrow></msup><mo>/</mo><msup><mi>ρ</mi><mo>′</mo></msup></mrow><mo>)</mo></mrow></mrow></math></span>, consistent with classical theory, although the crater depth is slightly overestimated for thick oil films due to an underestimation of viscous dissipation. The total crater energy accounts for approximately 27∼35% of the initial droplet impact energy for<span><math><mrow><mrow><mspace></mspace><mtext>Fr</mtext></mrow><mo>≥</mo><mn>100</mn></mrow></math></span>. Furthermore, the maximum jet length scales as <span><math><mrow><msup><mi>l</mi><mo>′</mo></msup><mo>∼</mo><mtext>We</mtext></mrow></math></span>, with jet pinch-off occurring when <span><math><mrow><msup><mi>l</mi><mo>′</mo></msup><mfrac><mo>&gt;</mo><mstyle><mo>∼</mo></mstyle></mfrac><mn>1.24</mn></mrow></math></span>, demonstrating the capability of the proposed multi-interfaces theory to capture crater and jet dynamics. The measured maximum jet length also falls into the classical scaling relationship with the effective Weber number. Finally, two main impact regimes are identified using the effective Weber number <span><math><mrow><mi>W</mi><msub><mi>e</mi><mrow><mi>e</mi><mo>_</mo><mi>h</mi></mrow></msub></mrow></math></span> in combination with the product of the Reynolds and Froude numbers <span><math><mrow><mi>R</mi><mi>e</mi><mi>F</mi><msub><mi>r</mi><mi>h</mi></msub></mrow></math></span>. Generally, the developed multi-interface theory can correctly estimate the effect of the oil layer on the impact dynamics.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"198 ","pages":"Article 105644"},"PeriodicalIF":3.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186567","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 mechanical model for the mixed-size particle splash process based on the stochastic particle-bed collision","authors":"Junqing Lei ,&nbsp;Guohua Wang ,&nbsp;Xiaojing Zheng","doi":"10.1016/j.ijmultiphaseflow.2026.105641","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105641","url":null,"abstract":"<div><div>Investigating the interaction between sand particles and an erodible bed is fundamental to understanding wind-blown sand saltation. Since natural sand beds consist of non-uniformly distributed mixed-size particles, the existing three-particle stochastic granular-bed collision model (TPSGCM) for single-size particles is insufficient. To address this, the present study has developed a mixed-size four-particle stochastic granular-bed collision model (FPSGCM) that incorporates the shielding effect. This effect is influenced by the relative size of the impacted and shielding particles, as well as their relative vertical position. The new FPSGCM accurately reproduces the splash process of mixed-size particles. When applied to simulate wind-blown sand flow, the model predictions for the sand transport rate, saltation length, and height are in better agreement with experimental and theoretical results.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"198 ","pages":"Article 105641"},"PeriodicalIF":3.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146116565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation on the coupling characteristics of air gun array bubbles","authors":"Shuna Wang ,&nbsp;Niannian Liu ,&nbsp;Shuai Zhang ,&nbsp;Hang Geng","doi":"10.1016/j.ijmultiphaseflow.2026.105643","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105643","url":null,"abstract":"<div><div>To investigate the underlying relationship between the mechanical structure of an air gun and its bubble pulsation, we developed a compressible jet-based model for air gun bubble dynamics using the computational fluid dynamics (CFD) software STAR-CCM+. This model facilitated a systematic analysis of the coupling characteristics of high-pressure air gun bubble arrays and the propagation patterns of pressure waves in their flow fields. By examining the air discharge process of air gun, the influence of its mechanical structure on the surrounding hydrodynamics was revealed. The results indicate that during the bubble collapse phase, a centripetal jet, accompanied by a high-pressure stagnation point, typically forms near the opening outside the air gun array. The study further demonstrates that a smaller inter-gun spacing leads to a longer bubble pulsation period, while the maximum bubble volume remains largely unchanged. A higher initial internal pressure results in an increased maximum bubble volume, a longer pulsation period, and a faster pressure wave propagation speed. Finally, the opening height was found to exert a significant influence on bubble pulsation when it falls outside a specific optimal range.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"198 ","pages":"Article 105643"},"PeriodicalIF":3.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186566","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":"Mechanisms of Interfacial Evolution in Droplet Impact on Superhydrophobic Cones","authors":"Xiaofei Hu ,&nbsp;Bing Zhu ,&nbsp;Mingyang Lv ,&nbsp;Wei Zhang","doi":"10.1016/j.ijmultiphaseflow.2026.105637","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105637","url":null,"abstract":"<div><div>Droplet impact on conical surfaces is relevant to both natural processes and industrial applications. This study examines the interfacial evolution of droplets impacting superhydrophobic cones through experiments, simulations, and theoretical analysis, focusing on the effects of Weber number and cone angle. Four distinct impact modes are identified: (I) complete rebound without penetration; (II) penetration with ring formation and complete rebound; (III) penetration with ring formation followed by breakup during retraction; and (IV) penetration with ring formation followed by breakup during spreading. Increasing Weber number enhances the maximum spreading factor and prolongs spreading time, while larger cone angles suppress spreading and reduce the corresponding time. For non-penetration cases (Mode I), a pancake-like theoretical model based on energy conservation accurately predicts the maximum spreading factor. Mechanistically, Modes I–II arise from the balance of inertia and surface tension, Mode III from Rayleigh–Plateau instability, and Mode IV from local necking-induced ring rupture.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"198 ","pages":"Article 105637"},"PeriodicalIF":3.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146116564","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":"Fall and fingering of miscible magnetic fluid drops in a Hele-Shaw cell","authors":"M.S. Krakov ,&nbsp;A.V. Chernyshov ,&nbsp;A.R. Zakinyan","doi":"10.1016/j.ijmultiphaseflow.2026.105639","DOIUrl":"10.1016/j.ijmultiphaseflow.2026.105639","url":null,"abstract":"<div><div>The presented study is the experimental and numerical investigation of the fall and fingering of miscible magnetic fluid drops with variable properties in a vertical Hele-Shaw cell under a uniform field normal to the cell plane. We revealed that fingering is possible in magnetic fields that exceed the critical value. For the kerosene-based magnetic fluid used in the experiment and a droplet with a radius of about 3 mm, the critical value of the magnetic field strength was about 2 kA/m. It was found numerically that the distance between the fingers is linearly related to the width of the gap in the Hele-Shaw cell, and for the studied cases it is described by the expression λ = 1.19δ for the magnetic field of about 15 kA/m. The distance between the fingers decreases with the increase of the magnetic field in the region of weak magnetic fields, and with a further increase of the magnetic field, it hardly changes. The velocity of the droplet fall is determined by its morphology. With an increase in the number of fingers, the velocity of the fall decreases significantly. With the maximum value of the parameters numerically studied, the fall velocity decreased 2.5 times. As the number of fingers increases, the rate of mixing of magnetic fluid with the environment increases sharply. During the drop-fall time, the maximum concentration of magnetic fluid decreased 4 times at the maximum value of the parameters studied. However, in the absence of a magnetic field, without fingering, it remained practically unchanged.</div></div>","PeriodicalId":339,"journal":{"name":"International Journal of Multiphase Flow","volume":"198 ","pages":"Article 105639"},"PeriodicalIF":3.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186569","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}