International Journal of Multiphase Flow最新文献

Molecular dynamics investigation of nanobubble collapse near a solid-liquid interface under realistic conditions 现实条件下固液界面附近纳米气泡崩塌的分子动力学研究

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-09-01 Epub Date: 2026-08-27 DOI: 10.1016/j.ijmultiphaseflow.2026.105899

Qingmiao Ding, Zipeng Wang, Jian Xu, Yanyu Cui

The collapse behavior of nanobubble in the vicinity of solid-liquid interface under impact loading critically influences material erosion, cavitation damage, and surface degradation in fluid-structure systems. This study employs the Reactive Molecular Dynamics (RMD) method to investigate the dynamic processes of nanobubble collapse near solid-liquid interface at realistic impact velocities. The simulation procedure involved initial Canonical ensemble (The NVT ensemble) equilibration of water molecules and iron atoms, followed by microcanonical ensemble (The NVE ensemble) impact loading via piston driving with an initial velocity of 5 km/s in the z-direction. We tracked the propagation of shock waves, the evolution of atomic velocity fields, and the spatiotemporal evolution of nanobubble radius, revealing complex deformation and collapse characteristics of nanobubble with different initial radius. Results show that nanobubble collapse morphology, energy localization effects, and momentum transfer to iron substrates are highly sensitive to nanobubble size. Notably, larger nanobubble induce local localized compressive-stress peaks that significantly alter substrate surface roughness and microstructural features, shedding light on potential mechanisms of surface erosion and fatigue initiation. This study elucidated the cavitation damage mechanism at the atomic scale, verified the reactive force field (ReaxFF) method's analytical capability in coupling chemical-mechanical responses under extreme conditions, and provided a theoretical basis for multi-scale modeling of cavitation erosion phenomena in engineering materials.

在冲击载荷作用下，固液界面附近纳米气泡的崩溃行为对流固体系中材料的侵蚀、空化损伤和表面降解具有重要影响。本研究采用反应分子动力学（RMD）方法研究了在实际冲击速度下纳米气泡在固液界面附近崩塌的动力学过程。模拟过程包括水分子和铁原子的初始正则系综（NVT系综）平衡，然后通过活塞驱动的微正则系综（NVE系综）在z方向上以5 km/s的初始速度进行冲击加载。通过对激波传播、原子速度场演化和纳米气泡半径时空演化的跟踪研究，揭示了不同初始半径纳米气泡的复杂变形和坍缩特征。结果表明，纳米气泡的坍塌形态、能量局域效应和动量传递对纳米气泡尺寸高度敏感。值得注意的是，较大的纳米气泡会诱发局部压缩应力峰值，从而显著改变基体表面粗糙度和微观结构特征，从而揭示表面侵蚀和疲劳引发的潜在机制。本研究阐明了原子尺度上的空化损伤机理，验证了反作用力场（ReaxFF）方法在极端条件下耦合化学-力学响应的分析能力，为工程材料中空化侵蚀现象的多尺度建模提供了理论依据。

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引用次数: 0

AC electrohydrodynamic control and predictive scaling of droplet length in flow-focusing microchannels 流动聚焦微通道中液滴长度的预测尺度及交流电流体动力控制

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-09-01 Epub Date: 2026-08-20 DOI: 10.1016/j.ijmultiphaseflow.2026.105893

Weiwei Xu, Xinyu Wang, Weizhao Yu, Qiang Li

In droplet microfluidics, active control via an AC electric field is widely adopted, offering rapid response and high control accuracy. However, existing studies still lack a comprehensive understanding of droplet dynamic behavior and reliable length prediction models under AC electric fields. To address this, a self-developed InterEHDFoam solver in OpenFOAM is used to systematically explore the regulation of droplet generation dynamics by AC electric field parameters within a flow-focusing microchannel. A predictive model that couples voltage and the flow rate ratio is also developed. The results indicate that changing the electrode position of the AC electric field enables bidirectional transitions between slug and dripping flow. Furthermore, considering how droplets in dripping flow deflect under an AC electric field, a quantitative correlation between the critical voltage and the flow rate ratio is obtained, with a relative prediction error of less than 9%. Finally, through force analysis of the droplet, prediction models for droplet length are derived for the two electrode configurations, exhibiting high predictive accuracy under low voltage conditions, with relative errors within 10%.

在液滴微流体中，通过交流电场进行主动控制被广泛采用，具有响应速度快、控制精度高等优点。然而，现有的研究仍然缺乏对交流电场作用下液滴动力学行为的全面认识和可靠的液滴长度预测模型。为了解决这个问题，使用OpenFOAM中自主开发的InterEHDFoam求解器系统地探索了流动聚焦微通道内交流电场参数对液滴生成动力学的调节。建立了电压与流量比耦合的预测模型。结果表明，改变交流电场的电极位置可以实现段塞流和滴流的双向转换。考虑交流电场作用下滴流中液滴的偏转，得到了临界电压与流量比的定量相关性，相对预测误差小于9%。最后，通过对液滴的受力分析，建立了两种电极结构下液滴长度的预测模型，在低压条件下具有较高的预测精度，相对误差在10%以内。

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引用次数: 0

Corrigendum to "Revealing the effective basal condition of geophysical granular flows" [International Journal of Multiphase Flow, 198 (2026) 105648] “揭示地球物理颗粒流的有效基础条件”的勘误表[j] .国际多相流学报，1998(2026):105648。

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-09-01 Epub Date: 2026-07-29 DOI: 10.1016/j.ijmultiphaseflow.2026.105865

Alexis Bougouin, Fabio Dioguardi, Giovanna Capparelli, Eugenio Nicotra, Roberto Sulpizio

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引用次数: 0

Numerical investigation of near-field spray dynamics from flat-fan nozzles for water-based sprayable putty: Effects of nozzle geometry, injection pressure, and thermal thinning temperature 水基可喷涂腻子的平扇喷嘴近场喷射动力学数值研究：喷嘴几何形状、喷射压力和热减薄温度的影响

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-09-01 DOI: 10.1016/j.ijmultiphaseflow.2026.105885

Lintao Huo, Ce Yang, Haifei Xia, Ying Liu, Yutu Yang, Enyi Ye

High-pressure airless spraying is an advanced process that combines high coating efficiency with uniform film thickness formation, and has been applied to the automated putty spray coating of rail vehicle sidewall panels. The atomization angle of the flat-fan nozzle is a critical parameter characterizing the liquid atomization process, directly affecting liquid sheet formation and primary breakup, which in turn governs the momentum, size, and spatial distribution of droplets during secondary breakup, and ultimately determines the deposition behavior on the target surface. As a shear-thinning and thermally thinning non-Newtonian fluid, the atomization quality of putty varies significantly with pressure and temperature. To gain deeper insight into the gas–liquid flow distribution and atomization behavior during putty spraying, numerical simulations of the atomization process of water-based acrylic putty are conducted based on an Eulerian–Lagrangian coupling approach. In this study, the XHD-series flat-fan nozzles are reverse-engineered, and near-field atomization simulations are performed using the VOF model to investigate the relationships between the V-groove geometry parameters — including notch depth and notch angle — and the atomization angle and flow rate. The numerical results are validated against high-speed imaging experiments. The study further systematically examines the spatiotemporal evolution of the flow field, encompassing the development characteristics of the near-field liquid sheet, surface wave fluctuations on the liquid sheet, the formation of the downstream fan-shaped atomization structure, and the wall deposition morphology of the spray.

高压无气喷涂是一种将涂装效率高与成膜厚度均匀相结合的先进工艺，已应用于轨道车辆侧壁板的自动腻子喷涂。平扇喷嘴的雾化角是表征液体雾化过程的关键参数，直接影响液片的形成和初次破碎，进而控制二次破碎过程中液滴的动量、大小和空间分布，最终决定目标表面的沉积行为。作为一种剪切减薄和热减薄的非牛顿流体，腻子的雾化质量随压力和温度的变化而显著变化。为了更深入地了解腻子喷涂过程中的气液流动分布和雾化行为，基于欧拉-拉格朗日耦合方法对水基丙烯酸腻子的雾化过程进行了数值模拟。在这项研究中，对xhd系列平面风扇喷嘴进行了逆向工程，并使用VOF模型进行了近场雾化模拟，以研究v型槽几何参数（包括缺口深度和缺口角）与雾化角和流量之间的关系。通过高速成像实验验证了数值计算结果。该研究进一步系统地考察了流场的时空演变，包括近场液片的发展特征、液片上的表面波波动、下游扇形雾化结构的形成以及喷雾的壁面沉积形态。

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引用次数: 0

Effects of initial ellipsoidal geometry on droplet deformation and unsteady drag in the bag-breakup regime 初始椭球几何形状对袋式破碎过程中液滴变形和非定常阻力的影响

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-08-01 Epub Date: 2026-07-18 DOI: 10.1016/j.ijmultiphaseflow.2026.105847

Hongyu Ju, Yue Li, Hongxia Liang, Longxi Zheng, Jianqin Suo

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.

气体流动中液滴的瞬态变形受初始液滴几何形状的强烈影响，而以往的研究大多集中在初始球形液滴上。在本研究中，采用大涡模拟（LES）和流体体积（VOF）方法，研究了初始长径比为1 ~ 5、倾角为0°~ 90°的初始椭球状液滴在袋式破碎状态下的变形。结果表明，椭球状液滴总体上遵循与球形液滴相似的变形顺序，从圆盘状结构向袋状结构演化，而具体形态、破碎时间和破碎模式仍强烈依赖于初始几何形状。对于等效迎风面直径的演化，建立了统一的分段相关关系，发现在目前的参数范围内，它可以很好地描述球形和椭球体的情况。初始长径比的增大抑制了等效迎风面直径的增长，而倾角的减小则促进了等效迎风面直径的增长，并可能促进袋裂向袋-雄蕊破碎的转变。初始几何形状也会改变尾迹结构和压力分布，从而影响非定常阻力响应：较大的展弦比往往会降低峰值阻力水平，而倾角主要通过尾迹不对称影响早期阻力振荡。总的来说，这些发现阐明了初始非球形几何形状在袋裂条件下液滴变形和气动响应中的作用，为未来非球形初始形状液滴的建模提供了物理基础。

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引用次数: 0

Impact of unconventional propeller geometries on tip vortex cavitation noise: A numerical study 非常规螺旋桨几何形状对叶顶涡空化噪声影响的数值研究

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-08-01 Epub Date: 2026-07-15 DOI: 10.1016/j.ijmultiphaseflow.2026.105843

Adrian Portillo-Juan, Simone Saettone, Esteban Ferrer

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

μ

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.

船舶螺旋桨产生的水下辐射噪声已成为一个主要的环境问题，特别是在地中海等生态敏感地区。在不同的空化形式中，叶尖涡空化是最持久和最主要的噪声源之一，通常需要非常规的叶片几何形状来有效缓解。本文研究了桨尖倾斜和螺旋桨环形几何形状对桨尖空化动力学和相关水声响应的影响。采用ranss - des框架，结合VOF空化模型和可渗透Ffowcs williams - hawkins声学类比，对三种螺旋桨构型在空化工况下进行了数值分析。所研究的几何形状包括传统的基线螺旋桨、压力侧导向的尖顶倾斜结构和基于基线几何形状的环面设计。结果表明，在150 Hz-6 kHz范围内，这两种非常规几何形状的声压级降低了20 dB (ref = 1 μPa)，而水动力效率没有明显损失。斜桨抑制了主涡，减弱了次涡的相互作用，降低了宽带声发射。此外，环面结构完全抑制了相干尖涡空化结构，产生了在所分析的情况中最稳定的声响应。总体而言，研究结果表明，非常规的叶尖几何形状可以在保持推进性能的同时显著减轻空化引起的噪音，支持其作为环境可持续船用推进解决方案的潜力。

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引用次数: 0

Experimental investigation of injection orientation on liquid jet dynamics in supersonic crossflow 超声速横流中喷射方向对液体射流动力学影响的实验研究

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-08-01 Epub Date: 2026-07-20 DOI: 10.1016/j.ijmultiphaseflow.2026.105849

Srinivas M.V.V., Arun Kumar Rajagopal

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 (

J_{l}

). 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

J_{l}

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.

本文研究了喷射器方向对液体射流破裂、激波结构和相关流动相互作用的影响。考虑了三种注入角度为135°、90°和45°的注入器配置。背光成像分析表明，135°逆流喷射时，由于超音速反流施加的强大气动力，液体射流在非常接近喷油器出口处破裂。相比之下，45°喷射情况下，由于液体柱上的气动载荷相对较弱，因此几乎没有破裂。在动量通量比（Jl）范围内，利用阴影成像技术研究了不同注入情况下的激波结构。135°喷射产生了更强的弓形激波，并且与其他喷射情况相比，弓形激波与顶壁的相互作用在较低的Jl值下从规则反射转变为马赫反射。更强的船首激波也会导致上游分离区域的增大和液体夹带的增加。动态模态分解进一步识别控制射流动力学的相干结构，其主导频率与从射流界面振荡和弓形激波运动中获得的频率相匹配。

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引用次数: 0

Corrigendum to “Influence of dissolved gas concentration on the lifetime of surface bubbles in volatile liquids” [Int. J. Multiph. Flow 196 (2026) 105580] “溶解气体浓度对挥发性液体中表面气泡寿命的影响”的勘误表[国际标准]。j . Multiph。第196(2026)105580条]

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-08-01 Epub Date: 2026-07-18 DOI: 10.1016/j.ijmultiphaseflow.2026.105845

Xin Li, Yanshen Li

引用次数: 0

Corrigendum to IJMF Article 105740 IJMF第105740条的勘误表

IF 3.9 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-08-01 Epub Date: 2026-06-23 DOI: 10.1016/j.ijmultiphaseflow.2026.105804

T. Daoud, T.L. Jackson, S. Balachandar

引用次数: 0

Impact of water droplet on oil films suspended over water bath: Crater and jet dynamics 水滴对悬浮在水浴上的油膜的影响：陨石坑和射流动力学

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2026-04-01 Epub Date: 2026-02-05 DOI: 10.1016/j.ijmultiphaseflow.2026.105644

Xiaolong He , Qian Yang , Haonan Peng , Linlin Fei , Jianmin Zhang , Ya-Ling He

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

d_{e}^{'} \sim (F r^{1 / 4} / ρ^{'})

, 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

Fr \geq 100

. Furthermore, the maximum jet length scales as

l^{'} \sim We

, with jet pinch-off occurring when

l^{'} \frac{>}{\sim} 1.24

, 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

W e_{e_h}

in combination with the product of the Reynolds and Froude numbers

R e F r_{h}

. Generally, the developed multi-interface theory can correctly estimate the effect of the oil layer on the impact dynamics.

在大量实验的基础上，研究了水浴液上水滴对油膜的撞击动力学，重点研究了关键参数（水滴尺寸、撞击速度和油膜厚度）对弹坑生长和射流形成的影响。考虑到变形液滴-空气、油-液滴和油水界面的表面能变化，提出了一个多界面理论来描述碰撞过程中表面能的总变化，从而得到了有效表面张力和韦伯数，用于后续分析。最大弹坑深度遵循标度系数~ (Fr1/4/ρ)，与经典理论一致，尽管由于对粘性耗散的低估，对厚油膜的弹坑深度估计略高。当fr≥100时，撞击坑总能量约占液滴初始撞击能量的27 ~ 35%。此外，最大射流长度范围为l′~ We，射流掐断发生在l′>； ~ 1.24，证明了所提出的多界面理论捕捉陨石坑和射流动力学的能力。实测的最大射流长度与有效韦伯数也符合经典的标度关系。最后，使用有效韦伯数Wee_h结合雷诺数和弗劳德数refh的乘积确定了两个主要的影响机制。一般来说，所建立的多界面理论可以正确地估计油层对冲击动力学的影响。

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引用次数: 0