Article
Physics, Fluids & Plasmas
Linlin Fei, Feifei Qin, Geng Wang, Kai H. Luo, Dominique Derome, Jan Carmeliet
Summary: In this work, a revised theoretical analysis of single droplet evaporation is presented for finite-size open systems, taking into consideration 2D and 3D cases. The classical D2-Law is found to be applicable only for 3D large systems, while deviations occur for small and/or 2D systems. Theoretical solutions for the temperature field are derived, and numerical simulations using the lattice Boltzmann method are performed, achieving remarkable agreement with the theoretical solution.
Article
Mechanics
Shuai Gong, Zhiheng Hu, Lining Dong, Ping Cheng
Summary: The curvature and temperature dependency of liquid-vapor surface tension is crucial in predicting the nucleation process of nanobubbles and nanodrops. In this study, a mesoscopic approach is used to quantify the curvature and temperature dependency of surface tension and Tolman length for real fluids. The approach provides a new avenue for accurately predicting nucleation processes in micro-/nanoscale phase change heat transfer.
Article
Mechanics
Rongzong Huang
Summary: We present a macroscopic dynamic van der Waals theory for liquid-vapor phase transition from mesoscopic perspectives offered by the kinetic model for multiphase fluids. The present dynamic equations are identical to the macroscopic equations recovered by the kinetic model, revealing the excess effects caused by unbalanced long-range molecular interaction in the inhomogeneous region.
Article
Thermodynamics
Chuangde Zhang, Li Chen, Wentao Ji, Yu Liu, Luguo Liu, Wen-Quan Tao
Summary: In this study, a MRT phase change lattice Boltzmann model was used to investigate flow boiling heat transfer processes in a vertical microchannel, and the heat transfer performance was enhanced by optimizing cavity microstructure. The simulation results show that increasing Reynolds number improves flow boiling heat transfer performance, advancing our understanding of bubble dynamics and heat transfer mechanisms in microchannel flow boiling processes.
APPLIED THERMAL ENGINEERING
(2021)
Article
Mechanics
Ying Zhang, Yu Mao, Yuan Tian, Yichen Huang, Jiansheng Liu, Zhaoqing Ke
Summary: A phase transition lattice Boltzmann model was used to simulate the pool boiling process on a triangular structure-roughened surface with conjugate heat transfer effect. The results showed that a hydrophilic surface inhibits bubble growth but facilitates bubble detachment, while a hydrophobic surface increases bubble growth but inhibits bubble detachment. The study also found that continuous wettability can improve the surface's heat transfer performance.
Article
Physics, Mathematical
F. Fadda, A. Lamura, A. Tiribocchi
Summary: In this study, numerical simulations were used to investigate the dynamics of quasi-two dimensional cholesteric liquid crystal droplets under the influence of a time-dependent electric field rotating at a constant angular velocity. The addition of a surfactant at the droplet interface prevented droplet coalescence. The results showed that the liquid crystal rotation caused concurrent orbital motion of the droplets around each other, and the topological defects exhibited chaotic-like motion in cholesterics with a high pitch.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2023)
Article
Mathematics, Applied
Michele La Rocca, Andrea Montessori, Pietro Prestininzi
Summary: In this paper, a mesoscale model for polar fluids is proposed and its validity is numerically investigated using well-known benchmark cases. The results show a good agreement between the analytical and numerical results, and the proposed model shows promise in handling high Reynolds lid-driven cavity flow.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Physics, Fluids & Plasmas
Surabhi Jaiswal, Soudamini Sahoo, Snigdha Thakur
Summary: A mesoscopic simulation model is proposed to study phase separation in a 3D binary fluid mixture by improving the existing particle-based multiparticle collision dynamics (MPCD) algorithm. The model incorporates the excluded-volume interaction between the two components to describe the nonideal equation of the fluid state within the framework of stochastic collision, which depends on the local fluid composition and velocity. The thermodynamic consistency of the model is confirmed by comparing the nonideal pressure contribution from simulation and analytics. A phase diagram is explored to investigate the parameter range for phase separation, and the model results agree with literature for various temperatures and parameters.
Article
Electrochemistry
Yu-Tong Mu, Shu-Ran Yang, Pu He, Wen-Quan Tao
Summary: This study investigates the local transport behaviors of oxygen in electrodes with different liquid water saturations and platinum distributions. The effective oxygen diffusivities decrease with the contact angle of the electrode, while the limiting current density decreases with the liquid water saturation.
ELECTROCHIMICA ACTA
(2021)
Article
Mechanics
Jinhua Hong, Yifan Jin, Yiwei Jin, Yulong Li, Jizhong Liu, Jiankui Chen
Summary: In this paper, the coalescence dynamics of droplet impacting on a rectangular pixel in OLEDs inkjet printing is simulated and analyzed using a dynamic model. The influences of droplet parameters on the coalescence dynamics are also studied.
Article
Engineering, Chemical
Shaojun Dou, Liang Hao, Hong Liu
Summary: In this study, the lattice Boltzmann pseudopotential model was applied to simulate the phase behavior of confined fluids and the physisorption process in nanopores. The simulation results showed that the model accurately described the thermodynamic and phase behaviors of confined fluids at the molecular level. Numerical adsorption experiments in nano-pores successfully captured the essential characteristics of different types of physisorption and revealed the underlying mechanisms of adsorption hysteresis induced by adsorption metastability and network effects.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Thermodynamics
Si Wu, Xiaochuan Liu, Keyong Zhu, Yong Huang
Summary: This paper proposes a mesoscopic lattice Boltzmann method (LBM) for solving simple steady-state and transient radiative transfer problems in three-dimensional (3D) graded index (GRIN) media. The concept of local radiative transfer direction is introduced to address complex curved trajectories in 3D GRIN media. Numerical results demonstrate the effectiveness of LBM in solving radiative transfer problems in 3D GRIN media. The influences of different optical parameters on steady-state and transient radiative transfer are discussed.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Polymer Science
Rami Alhasan, Douglas R. Tree
Summary: Phase-field models are cost-effective models capable of capturing the nonequilibrium multiphase behavior of polymers and soft materials. The thermodynamic consistency of some model formulations has been questioned, leading researchers to derive a generalized Gibbs-Duhem relation to ensure thermodynamic consistency. This derivation demonstrates that a phase-field model satisfying the Gibbs-Duhem expression is thermodynamically consistent.
Article
Thermodynamics
Yu Wang, Pengfei Liu, Hui Wang, Guangming Xiao, Yanxia Du
Summary: A comprehensive model that considers reaction morphology during the pyrolysis process in silica-phenolic composites at the pore scale is proposed using the Lattice Boltzmann method. The effects of fiber diameters and volume fractions on temperature and mass loss are investigated. Findings show that the matrix surrounding the silica fiber reacts first, followed by the matrix on the fiber surface during pyrolysis. Decreasing the silica fiber diameter increases the temperature of the composites, while reducing the fiber volume fraction decreases the mass loss. These findings provide essential thermal data for the design of reliable thermal protection structures using silica-phenolic composites.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Xin Wang, Jingyi Chang, Zhenqian Chen, Bo Xu
Summary: This study models dropwise condensation heat transfer on micropillared surfaces using the 2D multiphase lattice Boltzmann method. The investigation focuses on the dynamic evolution of condensate droplets and heat transfer performance with different surface wettability. The results show that weaker surface wettability leads to a decrease in condensate mass and critical departure radius of droplets.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2021)
Article
Mechanics
Mihir Durve, Adriano Tiribocchi, Fabio Bonaccorso, Andrea Montessori, Marco Lauricella, Jan Guzowski, Sauro Succi
Summary: Deep neural networks are powerful tools for data analysis in microfluidic systems, particularly in droplet counting and tracking. This study combines the YOLO and DeepSORT algorithms to create the image analysis tool DropTrack for droplet tracking in microfluidic experiments. Training the YOLO network with hybrid datasets improves the accuracy of droplet detection and counting in real experimental videos, while reducing the labor-intensive image annotation work. DropTrack's performance is evaluated based on mean average precision, mean squared error, and image analysis speed for droplet tracking.
Article
Mechanics
Valentina Lombardi, Michele La Rocca, Andrea Montessori, Sauro Succi, Pietro Prestininzi
Summary: Droplets impacting solid surfaces and jumping over gaps are common phenomena in both natural and industrial environments. Through experiments, it has been found that droplets can deform upon impact and climb sharp edges. This unique behavior is attributed to the conversion of rotational momentum into linear momentum. The study shows that droplets are more likely to jump over gaps compared to solid spheres. This research contributes to the understanding of the rotational speed of droplets on hydrophobic surfaces.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Pablo G. Tello, D. O. N. A. T. O. Bini, S. T. U. A. R. T. Kauffman, S. A. U. R. O. Succi
Summary: This letter proposes an approach to the vacuum energy and the cosmological constant (CC) paradox based on the Zel'dovich's ansatz, which states that the observable contribution to the vacuum energy density is given by the gravitational energy of virtual particle-antiparticle pairs. The novelty of this work is the use of an ultraviolet cut-off length based on the holographic principle, which yields current values of the CC in semi-quantitative agreement with experimental observations.
Article
Physics, Multidisciplinary
Marco Crialesi-Esposito, Sergio Chibbaro, Luca Brandt
Summary: Through a fully-coupled numerical study, we have found that a quantitative theory is lacking for the dynamics of droplet fragmentation in turbulence at high concentrations and strong interactions. By employing time-space spectral statistics, we have identified the characteristic scale of the process, known as the Hinze scale, as the scale at which the net energy exchange due to capillarity is zero. This study also reveals the link between the droplet-size distribution and the probability distribution of turbulent dissipation.
COMMUNICATIONS PHYSICS
(2023)
Article
Physics, Mathematical
Daniele Simeoni, Alessandro Gabbana, Sauro Succi
Summary: In this work, we provide both analytic and numerical solutions for the Bjorken flow, which is a standard benchmark in relativistic hydrodynamics. It offers a simple model for the macroscopic evolution of matter produced in heavy nucleus collisions. We consider relativistic gases with both massive and massless particles, working in a (2+1) and (3+1) Minkowski spacetime coordinate system. The numerical results obtained from a newly developed lattice kinetic scheme show excellent agreement with the analytic solutions.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2023)
Article
Physics, Mathematical
Giacomo Falcucci, Giorgio Amati, Pierluigi Fanelli, Sauro Succi, Maurizio Porfiri
Summary: This study investigates the flow characteristics of the Hexactinellid Sponge Euplectella aspergillum using large-scale simulations. The findings reveal the evolutionary adaptations of deep-sea sponges to fluid flow and open up new possibilities for interdisciplinary research in physics, engineering, and biology at the ocean interface.
COMMUNICATIONS IN COMPUTATIONAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Roberto Benzi, Thibaut Divoux, Catherine Barentin, Sebastien Manneville, Mauro Sbragaglia, Federico Toschi
Summary: Soft Glassy Materials (SGM) are dense amorphous assemblies of colloidal particles with diverse shapes, elasticity, and interactions, giving them solid-like properties at rest. They are widely used in modern engineering fields such as additive manufacturing, semi-solid flow cells, dip coating, and adhesive locomotion, and often undergo a solid-to-liquid transition induced by shear. In this article, we propose a continuum model based on a spatially resolved fluidity approach to explain shear-induced yielding in SGMs. Our model captures quantitatively the key features of complex flows in SGMs, including the rate dependence of stress overshoot, transient shear-banded flows, and scaling laws for fluidization times.
Article
Chemistry, Physical
Mihir Durve, Sibilla Orsini, Adriano Tiribocchi, Andrea Montessori, Jean-Michel Tucny, Marco Lauricella, Andrea Camposeo, Dario Pisignano, Sauro Succi
Summary: Tracking droplets in microfluidics is a challenging task, and choosing a tool to analyze microfluidic videos is difficult. The YOLO and DeepSORT algorithms are used for droplet identification and tracking by training networks. Several YOLOv5 and YOLOv7 models and the DeepSORT network were trained for droplet tracking. Performance comparison between YOLOv5 and YOLOv7 in terms of training time and video analysis time was conducted. Real-time tracking was achieved with lighter YOLO models on RTX 3070 Ti GPU due to additional droplet tracking costs from the DeepSORT algorithm. This work serves as a benchmark study for YOLOv5 and YOLOv7 networks with DeepSORT for microfluidic droplet analysis.
EUROPEAN PHYSICAL JOURNAL E
(2023)
Article
Chemistry, Physical
Adriano Tiribocchi, Andrea Montessori, Giorgio Amati, Massimo Bernaschi, Fabio Bonaccorso, Sergio Orlandini, Sauro Succi, Marco Lauricella
Summary: A regularized version of the lattice Boltzmann method is proposed for efficient simulation of soft materials. It reconstructs the distribution functions from available hydrodynamic variables without storing the full set of discrete populations, leading to lower memory requirements and data access costs. Benchmark tests validate the method's effectiveness for simulating soft matter systems, particularly on future exascale computers.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Gianni V. Vinci, Roberto Benzi, Maurizio Mattia
Summary: Despite the complexity and stochastic nature of brain networks, a theory for the dynamics of finite assemblies of spiking neurons is lacking. In this study, we fill this gap by extending the population density approach to include a size-dependent stochastic source in the Fokker-Planck equation. We analytically characterize the finite-size noise in this equation, providing a self-consistent and nonperturbative description of the neuronal dynamics valid for a wide range of networks.
PHYSICAL REVIEW LETTERS
(2023)
Article
Mechanics
A. Tiribocchi, M. Durve, M. Lauricella, A. Montessori, D. Marenduzzo, S. Succi
Summary: Active droplets are artificial microswimmers that exhibit self-propelled motion. The authors study the effect of activity on a droplet containing a contractile polar fluid confined within microfluidic channels of various sizes. They find a range of shapes and dynamic regimes, regulated by contractile stress, droplet elasticity, and microchannel width.
Article
Physics, Particles & Fields
Andrea Solfanelli, Stefano Ruffo, Sauro Succi, Nicolo Defenu
Summary: In this study, we investigate the asymptotic behavior of the entanglement entropy for Kitaev chains with long-range hopping and pairing couplings. We find that the system exhibits an extremely rich phenomenology due to its truly non-local nature. In the strong long-range regime, we observe logarithmic, fractal, or volume-law entanglement scaling depending on the values of the chemical potential and power law decay strength.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Review
Physics, Fluids & Plasmas
Vincent Labarre, Stephan Fauve, Sergio Chibbaro
Summary: The study focuses on the transitions among different regimes in thermal convection, particularly the transition at higher Rayleigh number. Through numerical and analytical approaches, it is found that the transition can be clearly identified by considering the fluctuations of the heat flux. This transition is displayed by a jump of the ratio of the root-mean-square fluctuations of the heat flux to its mean value and occurs at Ra/Pr approximate to 109.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Mechanics
M. Crialesi-Esposito, G. Boffetta, L. Brandt, S. Chibbaro, S. Musacchio
Summary: This study investigates the statistics of turbulence in emulsions of two immiscible fluids of the same density. The presence of the interface reduces the energy flux towards dissipative scales, and multiphase turbulence is more intermittent than single-phase turbulence.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Multidisciplinary Sciences
Roberto Benzi, Angelo Vulpiani
Summary: The introduction of the multifractal description in the 1980s played an important role in the fields of statistical physics, chaos, and disordered systems. It provided a way to characterize the anomalous scaling of fully developed turbulence and clarified the inaccuracy of the common idea from critical phenomena that only a few scaling exponents are relevant.
RENDICONTI LINCEI-SCIENZE FISICHE E NATURALI
(2022)
