International Journal of Multiphase Flow最新文献_第6页

A weakly-compressible DEM–CFD framework for dense gas–solid multiphase flows: Foundations consistent with reactive coupling 致密气固多相流弱可压缩DEM-CFD框架：符合反应耦合的基础

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-27 DOI: 10.1016/j.ijmultiphaseflow.2025.105558

Yuki Yakata , Kimiaki Washino , Masaya Muto , Ryoichi Kurose , Takuya Tsuji

The design of large-scale multiphase reactors, such as fluidized beds for methanation, requires numerical methods that are both computationally efficient and physically accurate. This study addresses the limitations of existing approaches, where traditional DEM–CFD solvers are often computationally expensive and computationally less expensive methods typically fail to capture crucial physical phenomena such as finite-speed acoustic waves. We present a novel DEM–CFD framework for low-Mach number flows that couples the Discrete Element Method (DEM) with a non-iterative, weakly-compressible fractional-step method for the gas phase. This approach combines the particle-scale accuracy of DEM with a gas solver that efficiently handles both density variations and acoustic wave propagation. As a fundamental step before simulating reactive flows, this paper validates the framework’s hydrodynamic and acoustic capabilities using non-reactive test cases. First, simulations of pressure drop across a fixed bed show excellent agreement with the Ergun equation, validating the momentum exchange model. Second, the complex dynamics of a spout-fluidized bed are shown to reproduce experimental trends, while also highlighting the simulation’s sensitivity to particle contact parameters like restitution and friction coefficients. Finally, speed of sound measurements in various gases (Dry Air, CO

_{2}

, H

_{2}

) within a particle bed confirm the framework’s ability to accurately capture finite sound speed and species-dependent properties, with results aligning well with pure-gas theory. The framework’s flexibility was further demonstrated by successfully reproducing an alternative ”frozen” two-phase sound speed. These comprehensive validations demonstrate the framework’s capability as a robust and efficient tool for investigating complex reactive multiphase flows.

大型多相反应器（如甲烷化流化床）的设计需要计算效率高、物理精度高的数值方法。该研究解决了现有方法的局限性，传统的DEM-CFD求解器通常计算成本昂贵，而计算成本较低的方法通常无法捕获关键的物理现象，如有限速度声波。我们提出了一种新的低马赫数流动的DEM - cfd框架，该框架将离散元法（DEM）与气相的非迭代、弱可压缩分步法相结合。该方法将DEM的粒子尺度精度与气体求解器相结合，有效地处理密度变化和声波传播。作为模拟反应性流之前的基本步骤，本文使用非反应性测试用例验证了框架的水动力和声学能力。首先，固定床上压降的模拟结果与Ergun方程非常吻合，验证了动量交换模型。其次，喷流化床的复杂动力学可以再现实验趋势，同时也突出了模拟对颗粒接触参数（如恢复和摩擦系数）的敏感性。最后，对颗粒床内不同气体（干燥空气、二氧化碳、氢气）的声速进行测量，证实了该框架能够准确捕捉有限声速和物种相关特性，结果与纯气体理论非常吻合。通过成功再现另一种“冻结”两相声速，进一步证明了该框架的灵活性。这些全面的验证证明了该框架作为研究复杂反应多相流的强大而有效的工具的能力。

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引用次数: 0

Segmenting the complex and irregular in two-phase flows: A real-world empirical Study with SAM2 两相流中复杂和不规则的分割：基于SAM2的现实世界实证研究

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-25 DOI: 10.1016/j.ijmultiphaseflow.2025.105557

Semanur Küçük, Cosimo Della Santina, Angeliki Laskari

Segmenting gas bubbles in multiphase flows is a critical yet unsolved challenge in numerous industrial settings, from metallurgical processing to maritime drag reduction. Traditional approaches — and most recent learning-based methods — assume near-spherical shapes, limiting their effectiveness in regimes where bubbles undergo deformation, coalescence, or breakup. This complexity is particularly evident in air lubrication systems, where coalesced bubbles form amorphous and topologically diverse patches. In this work, we revisit the problem through the lens of modern vision foundation models. We cast the task as a transfer learning problem and demonstrate, for the first time, that a fine-tuned Segment Anything Model (SAM v2.1) can accurately segment highly non-convex, irregular bubble structures using as few as 100 annotated images.

在许多工业环境中，从冶金加工到海上减阻，多相流中的气泡分割是一个关键但尚未解决的挑战。传统的方法——以及最近的基于学习的方法——假设接近球形，限制了它们在气泡变形、合并或破裂的情况下的有效性。这种复杂性在空气润滑系统中尤为明显，在空气润滑系统中，气泡会形成无定形的、拓扑结构多样的斑块。在这项工作中，我们通过现代视觉基础模型的镜头重新审视这个问题。我们将该任务作为一个迁移学习问题，并首次证明了微调的分割任意模型（SAM v2.1）可以使用少至100个注释图像准确分割高度非凸、不规则的气泡结构。

引用次数: 0

Enhancement of pool boiling heat transfer using eco-hybrid nanofluids 生态混合纳米流体增强池沸腾传热

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-24 DOI: 10.1016/j.ijmultiphaseflow.2025.105559

Raju Kumar , Pravin Pranav , Rinku Kumar Gouda , Akash Priy , Manabendra Pathak , Mohd. Kaleem Khan , Md. Shamim Shah

This draft explores an experimental investigation into improving pool boiling heat transfer through the use of eco-friendly hybrid nanofluids. The proposed eco-friendly hybrid nanofluids have been prepared using Rhamnolipid surfactant particles, Magnesium Oxide (MgO), and water. Four samples of hybrid nanofluids have been prepared by keeping Rhamnolipid surfactant at the critical micelles concentration and by varying the MgO concentrations as 0.5g/l, 0.05g/l, 0.005g/l, and 0.0005 g/l in deionized water. The detailed characterization and stability analysis of the hybrid nanofluids were performed. Roughness and wettability of fresh and post-boiling surfaces have been analyzed to check their influence on the heat transfer process. The hybrid nanofluid has a thermal conductivity of 4-9 % greater than DI water, where its surface tensions are 43 % - 53 % lower than those of pure DI water. The investigations were carried out on a smooth copper surface and at atmospheric conditions. The developed hybrid nanofluid enhances both the heat transfer rate and the critical heat flux (CHF) compared to pure water. The heat transfer coefficient (HTC) is observed to increase by 1.16 to 1.79 times, and the CHF is increased by 1.41 to 1.61 times. The result for improved heat transfer in eco-hybrid nanofluids is due to the decrease in surface tension, which has initiated more nucleation sites than pure water, increase in porosity and surface roughness due to the deposition of nanoparticles and surfactant monomers, improved surface wettability, and better rewetting phenomena.

本草案探讨了通过使用生态友好型混合纳米流体改善池沸腾传热的实验研究。采用鼠李糖脂表面活性剂颗粒、氧化镁（MgO）和水制备了环保型混合纳米流体。将鼠李糖脂表面活性剂保持在临界胶束浓度，在去离子水中MgO浓度分别为0.5g/l、0.05g/l、0.00g /l和0.0005 g/l，制备了4种杂化纳米流体样品。对混合纳米流体进行了详细的表征和稳定性分析。分析了新鲜表面和沸腾后表面的粗糙度和润湿性，以检查它们对传热过程的影响。混合纳米流体的导热系数比去离子水高4- 9%，其表面张力比纯去离子水低43% - 53%。研究是在光滑的铜表面和大气条件下进行的。与纯水相比，混合纳米流体的传热速率和临界热流密度均有所提高。传热系数（HTC）增加了1.16 ~ 1.79倍，CHF增加了1.41 ~ 1.61倍。生态杂化纳米流体传热改善的结果是由于表面张力的降低（与纯水相比，表面张力产生了更多的成核位点）、纳米颗粒和表面活性剂单体的沉积增加了孔隙度和表面粗糙度、表面润湿性的改善以及更好的再润湿现象。

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引用次数: 0

Beyond the Cassie–Baxter model: New insights for predicting imbibition in complex systems 超越Cassie-Baxter模型：预测复杂系统渗吸的新见解

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-24 DOI: 10.1016/j.ijmultiphaseflow.2025.105560

Mathis Fricke , Lisanne Gossel , Joël De Coninck

We revisit the classical problem of liquid imbibition in a single tube with spatially varying wettability. Starting from the Lucas–Washburn equation, we derive analytical solutions for the imbibition time (crossing time) in systems where wettability alternates between different materials. For ordered arrangements, we demonstrate that the imbibition speed depends non-trivially on the spatial distribution, with the ”more hydrophobic-first” configuration being optimal. For disordered systems, where segment lengths follow a Gaussian distribution, we show that the classical Cassie–Baxter contact angle, originally derived for static wetting, fails to predict the dynamics of capillary-driven flow. To address this, we propose a new weighted harmonic averaging method for the contact angle, which accurately describes the viscous crossing time in such heterogeneous systems. Our findings reveal fundamental insights into the role of wettability heterogeneity in capillary-driven flow, offering a basis for understanding imbibition dynamics in complex heterogeneous systems.

The research data and the software supporting this study are openly available at DOI:10.5281/zenodo.14537452.

我们重新审视了具有空间变化润湿性的单管中液体吸吮的经典问题。从Lucas-Washburn方程出发，我们推导出了不同材料之间润湿性交替的系统中吸胀时间（穿越时间）的解析解。对于有序排列，我们证明了吸胀速度与空间分布有很大关系，“更疏水优先”的配置是最优的。对于片段长度服从高斯分布的无序系统，我们表明，最初为静态润湿导出的经典Cassie-Baxter接触角无法预测毛细管驱动流动的动力学。为了解决这个问题，我们提出了一种新的加权谐波平均接触角方法，该方法可以准确地描述这种非均质系统中的粘性穿越时间。我们的研究结果揭示了润湿性非均质性在毛细管驱动流体中的作用，为理解复杂非均质系统中的吸胀动力学提供了基础。研究数据和支持本研究的软件可在DOI:10.5281/zenodo.14537452上公开获取。

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引用次数: 0

Numerical study of spray cooling: The effect of nozzle arrangement on heat transfer performance 喷雾冷却的数值研究：喷嘴布置对传热性能的影响

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-24 DOI: 10.1016/j.ijmultiphaseflow.2025.105561

Qingshan Chen , Qinrui Zhang , Cong Wang , Kailun Guo , Mingjun Wang , Xiaoyan Wang , Wenxi Tian , Suizheng Qiu , Guanghui Su

Spray cooling technology, known for its high heat transfer efficiency, is widely applied in high heat flux scenarios. However, existing studies often lack efficient model transition strategies for simulating droplet impingement, liquid film formation, and evaporative heat and mass transfer processes, resulting in high computational costs and limited applicability to large-scale fields. This study proposes an innovative numerical spray cooling method called DPM-VOF-LEE. It integrates Volume of Fluid (VOF) and Discrete Phase Model (DPM) with an evaporative heat transfer model through a transition strategy. The DPM model is employed for efficient droplet tracking in the far-field region. In contrast, the VOF model is applied near the wall to resolve liquid film morphology and heat transfer accurately. This model transition method significantly reduces mesh requirements and improves scalability. It is especially suitable for large-area or multi-nozzle spray cooling systems. Results indicate that vertical single-nozzle spraying exhibits the best cooling performance. In dual-nozzle configurations, interference regions enhance heat transfer. Cooling efficiency increases by more than 78 % compared with non-interference cases. For triple-nozzle configurations, the staggered layout achieves faster average temperature reduction on aluminum plates, with cooling efficiency 8.32 % higher than the inline layout.

喷雾冷却技术以其高传热效率而闻名，广泛应用于高热流密度的场合。然而，现有研究往往缺乏有效的模型转换策略来模拟液滴撞击、液膜形成和蒸发传热传质过程，导致计算成本高，对大尺度领域的适用性有限。本研究提出一种创新的数值喷雾冷却方法DPM-VOF-LEE。它通过转换策略将流体体积（VOF）和离散相模型（DPM）与蒸发传热模型相结合。采用DPM模型对液滴进行远场跟踪。而在壁面附近采用VOF模型可以准确地解析液膜形态和传热。这种模型转换方法显著降低了网格需求，提高了可扩展性。特别适用于大面积或多喷嘴喷雾冷却系统。结果表明，垂直单喷嘴喷射冷却效果最好。在双喷嘴结构中，干涉区增强了传热。与无干扰情况相比，冷却效率提高了78%以上。对于三喷嘴配置，交错布局可以更快地降低铝板的平均温度，冷却效率比直线布局高8.32%。

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引用次数: 0

Particle-laden gravity currents: The lock-release slumping regime at the laboratory scale 满载粒子的重力流：实验室尺度下的锁释塌缩状态

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-20 DOI: 10.1016/j.ijmultiphaseflow.2025.105539

C. Gadal , J. Schneider , C. Bonamy , J. Chauchat , Y. Dossmann , S. Kiesgen de Richter , M.J. Mercier , F. Naaim-Bouvet , M. Rastello , L. Lacaze

This study investigates the early slumping regime of particle-laden gravity currents from full-depth dam-break releases, combining laboratory experiments and two-fluid simulations. By systematically exploring the parameter space, it highlights the influence of the bottom slope, particle volume fraction and particle settling velocity on the flow dynamics.

本研究结合实验室实验和双流体模拟，研究了全深度溃坝释放中载重粒子重力流的早期滑塌状态。通过系统地探索参数空间，突出了底部坡度、颗粒体积分数和颗粒沉降速度对流动动力学的影响。

引用次数: 0

Comparative study of aerosol and hydrosol transport and deposition dynamics in turbulent wall-bounded flows 湍流壁面流动中气溶胶和纯溶胶输运和沉积动力学的比较研究

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-19 DOI: 10.1016/j.ijmultiphaseflow.2025.105551

S. Abbasi, A. Mehdizadeh

Understanding particle transport and deposition in wall-bounded turbulent flows is critical for numerous industrial and environmental applications. In this study, we investigate the dispersion and deposition dynamics of small aerosol and hydrosol particles in a turbulent channel flow at a friction Reynolds number of

R e_{τ} = 180

using point-particle direct numerical simulations (PP–DNS). By decomposing the particle acceleration into drag, lift, pressure gradient, virtual mass, and Basset history components, we assess the relative influence of each acceleration across a range of particle sizes and density ratios (aerosol and hydrosol) in an upward flow motion, i.e. opposite direction of gravity. Our results show that while drag dominates the particle dynamics particularly for aerosols, lift becomes increasingly important with rising particle size. The Basset history, pressure gradient and virtual mass accelerations have only a negligible contribution to the total acceleration. Regarding hydrosol, pressure gradient has a constant contribution to particle acceleration, largely independent of particle size, where the effect of virtual mass decreases with the increase of particle size. On the other hand, Basset history acceleration, shows size-dependent behavior. For small particles, the Basset history acceleration contributes to the particle acceleration with a magnitude comparable to the pressure gradient. As the particle size increases, this contribution decreases, and its dynamics changes once the hydrosol particle size approaches the Kolmogorov scale. Additionally, both pressure gradient and Basset history have significant input on deposition for hydrosol particles comparable to Kolmogorov length scale.

了解颗粒在壁面湍流中的传递和沉积对于许多工业和环境应用至关重要。在这项研究中，我们使用点粒子直接数值模拟（PP-DNS）研究了摩擦雷诺数Reτ=180时湍流通道中气溶胶和纯溶胶小颗粒的分散和沉积动力学。通过将粒子加速度分解为阻力、升力、压力梯度、虚拟质量和Basset历史分量，我们评估了在向上流动运动（即与重力相反的方向）中，每个加速度在不同粒径和密度比（气溶胶和纯溶胶）范围内的相对影响。我们的研究结果表明，虽然阻力在颗粒动力学中起主导作用，特别是对于气溶胶，但随着颗粒尺寸的增大，升力变得越来越重要。巴塞特历史、压力梯度和虚质量加速度对总加速度的贡献可以忽略不计。对于纯溶胶，压力梯度对粒子加速度的贡献是恒定的，在很大程度上与粒径无关，其中虚质量的影响随着粒径的增大而减小。另一方面，Basset历史加速显示了依赖于大小的行为。对于小颗粒，巴塞特历史加速度对颗粒加速度的贡献与压力梯度的大小相当。随着粒径的增大，这一贡献减小，当纯溶胶粒径接近柯尔莫哥洛夫尺度时，其动力学特性发生变化。此外，压力梯度和Basset历史对可与Kolmogorov长度尺度相比较的纯溶胶颗粒的沉积有重要的影响。

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引用次数: 0

Controlling Taylor bubble migration in a non-concentric annulus: full-scale experiments applied to well drilling operations 控制泰勒气泡在非同心环空中的迁移：应用于钻井作业的全尺寸实验

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-19 DOI: 10.1016/j.ijmultiphaseflow.2025.105553

Eric R. Upchurch , Yaxin Liu , Evren M. Ozbayoglu

An experimental investigation into Taylor bubble countercurrent behavior in an eccentric 0.1524 m x 0.1016 m (6 in. x 4 in.) annulus using non-Newtonian fluids is presented. This annulus configuration and the fluids tested are commonly used in oil, gas and geothermal drilling operations, but are not reflected in the existing research literature. Fluid rheology, annulus inclination, and internal pipe rotational speed are varied to provide an understanding of Taylor bubble physics under countercurrent flow and its implications for effectively managing unwanted upward gas migration that can occur in a wellbore during drilling operations in fractured or vugular rock formations.

Water and Bingham plastic fluids of ever-increasing plastic viscosity (μ_p) and yield point (τ_y) are tested to determine the minimum average downward fluid velocity (i.e.,

{\overline{V}}_{\min}

) that each requires to halt Taylor bubble migration. Increases in μ_p and τ_y do not monotonically reduce

{\overline{V}}_{\min}

. Instead, moderate increases up to μ_p = 31 cP and τ_y = 40 lb/100 ft² increase

{\overline{V}}_{\min}

– while further increases in μ_p and τ_y reduce

{\overline{V}}_{\min}

, but at the cost of increased friction pressures in the wellbore. Accepting a larger

{\overline{V}}_{\min}

reduces friction pressures but requires using larger fluid volumes during the drilling process. Conversely, minimizing

{\overline{V}}_{\min}

induces higher friction pressure on the wellbore. Determining the appropriate balance of these factors, and others, when planning drilling operations requires integrating the findings of our low-pressure experiments with that of recently published high-pressure Taylor bubble migration experiments. A discussion of the various considerations in such planning is presented.

实验研究了偏心0.1524 m x 0.1016 m (6 in。介绍了使用非牛顿流体的x4英寸)环空。这种环空结构和测试的流体通常用于石油、天然气和地热钻井作业，但在现有的研究文献中没有反映出来。流体流变学、环空倾斜度和管内旋转速度的变化，提供了对逆流作用下泰勒气泡物理特性的理解，以及它对有效管理压裂或空化岩层钻井作业期间井筒中可能出现的有害向上运移的影响。测试了不断增加的塑性粘度（μp）和屈服点（τy）的水和宾厄姆塑性流体，以确定最小的平均向下流体速度（即V - min），每个流体都需要停止泰勒气泡迁移。μp和τy的增加不会单调地减少V的最小值。相反，适度增加到μp = 31 cP和τy = 40 lb/100 ft2会增加V的min，而μp和τy的进一步增加会减少V的min，但代价是增加井筒中的摩擦压力。接受较大的V - min可以减少摩擦压力，但在钻井过程中需要使用较大的流体体积。相反，最小化V - min会在井筒上产生更高的摩擦压力。在规划钻井作业时，需要将我们的低压实验结果与最近发表的高压Taylor气泡迁移实验结果相结合，以确定这些因素以及其他因素的适当平衡。讨论了这种规划中的各种考虑因素。

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引用次数: 0

Molecular dynamics study of boiling on the surface of hybrid wettability rectangular cavity nanostructures 杂化润湿性矩形空腔纳米结构表面沸腾的分子动力学研究

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-19 DOI: 10.1016/j.ijmultiphaseflow.2025.105555

Dongling Liu, Xiaoping Luo, Yijie Fan, Jinxin Zhang

This study explores the influence of rectangular cavity wettability and size on explosive boiling through nonequilibrium molecular dynamics (MD) simulations. Hybrid wettability rectangular cavity nanostructured surfaces (HWRN) were constructed. Among them, surfaces HWRN-A1 to HWRN-A6 represent a gradual decrease in cavity wettability, while surfaces HWRN-B1 to HWRN-B6 correspond to a gradual increase in the area ratio of the superhydrophobic cavity surface. The atomic energy distribution of the argon liquid film was analyzed to investigate the mechanism of surface wettability on bubble nucleation. The heated surface temperature increased from 90 K to 180 K in 15 ns (6K/ns). The simulation results indicate that reducing the wettability of the rectangular cavities on the HWRN-A surface shortens the time for both bubble nucleation and explosive boiling. The explosive boiling time of HWRN-A6 (superhydrophobic cavity) is 225 ps earlier than that of HWRN-A1 (superhydrophilic cavity). The bubble nucleation time demonstrates a decreasing then increasing trend with the expansion of HWRN-B's cavity area. Under the conditions of this study, the optimal area ratio of HWRN-B was 8% (B3). The surfaces with the largest CHF in the HWRN-A and HWRN-B groups of studies were HWRN-A6 (5.4 × 10^–4eV/(nm²·ps)) and HWRN-B3 (5.7 × 10^–4 eV/(nm²·ps)), respectively.

通过非平衡分子动力学（MD）模拟，探讨了矩形空腔润湿性和尺寸对炸药沸腾的影响。构建了混合润湿性矩形腔纳米结构表面（HWRN）。其中，HWRN-A1 ~ HWRN-A6表面表征腔体润湿性逐渐降低，HWRN-B1 ~ HWRN-B6表面表征超疏水腔体表面面积比逐渐增加。分析了氩气液膜的原子能量分布，探讨了表面润湿性对气泡成核的影响机理。加热表面温度在15 ns （6K/ns）内由90k升高到180k。模拟结果表明，降低HWRN-A表面矩形空腔的润湿性可缩短气泡成核和爆炸沸腾的时间。超疏水空腔HWRN-A6的爆炸沸腾时间比超亲水空腔HWRN-A1的早225 ps。随着HWRN-B空泡面积的扩大，气泡成核时间呈现先减小后增大的趋势。在本研究条件下，HWRN-B的最佳面积比为8% （B3）。HWRN-A组和HWRN-B组表面CHF最大的分别是HWRN-A6 （5.4 × 10-4eV /(nm2·ps)）和HWRN-B3 （5.7 × 10-4eV /(nm2·ps)）。

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引用次数: 0

Numerical modeling of coalescence of two equal-sized droplets coated with particles 两个包覆粒子的等大小液滴聚结的数值模拟

IF 3.8 2区工程技术 Q1 MECHANICS

International Journal of Multiphase Flow

Pub Date : 2025-11-18 DOI: 10.1016/j.ijmultiphaseflow.2025.105554

Hanlin Zhou , Ningjing Mao , Yong Liu , Hong Liang , Haihu Liu

Coalescence dynamics of two equal-sized droplets coated with a fixed number of particles is numerically investigated using the lattice Boltzmann color-gradient model coupled with particle dynamics. By varying particle distribution range, we first show that the addition of particles can retard droplet deformation, and even in the absence of particles in the growth region of liquid bridge, more particles distributed at the axial ends of droplets significantly hinder droplet deformation. This is mainly because high kinetic energy region, which is concentrated at the axial ends of the droplet, is inhibited by particles in this region. We then vary the viscosity ratio of ambient fluid to droplet and find that for a moderate viscosity ratio, decreasing the particle distribution range causes the droplet oscillation mode to shift from critically damped to overdamped. In the under-damped mode, droplets are able to reach steady state earlier with a decrease in particle distribution range, while an opposite trend is observed in the overdamped mode. We also demonstrate that in addition to introducing particles, the reduction of particle distribution range equally contributes to increasing apparent viscosity of the ambient fluid. Finally, it is found that as the contact angle decreases, the damping ratio of droplet oscillations increases due to increased viscous dissipations and thus the maximum kinetic energy that the droplet can achieve decreases. As the particle distribution range increases, the effect of particles on droplet oscillations weakens, gradually making total kinetic energy and droplet deformation evolution curves for different contact angles indistinguishable.

采用结合粒子动力学的晶格玻尔兹曼颜色梯度模型，对包覆固定数量粒子的两个等大小液滴的聚结动力学进行了数值研究。通过改变颗粒分布范围，我们首先发现颗粒的加入可以延缓液滴变形，即使在液桥生长区域没有颗粒的情况下，液滴轴端分布较多的颗粒也会显著阻碍液滴变形。这主要是因为集中在液滴轴端的高动能区域受到该区域颗粒的抑制。然后，我们改变环境流体与液滴的粘度比，发现在中等粘度比下，减小颗粒分布范围会导致液滴的振荡模式从临界阻尼转变为过阻尼。在欠阻尼模式下，液滴能够更早达到稳态，颗粒分布范围减小，而在过阻尼模式下则相反。我们还证明，除了引入颗粒外，颗粒分布范围的缩小同样有助于增加周围流体的表观粘度。最后发现，随着接触角的减小，由于黏性耗散的增加，液滴振荡的阻尼比增大，液滴能达到的最大动能减小。随着颗粒分布范围的增大，颗粒对液滴振荡的影响减弱，逐渐使不同接触角下的总动能和液滴变形演化曲线难以区分。

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引用次数: 0