The European Physical Journal E最新文献_第3页

Numerical simulation study on drag reduction performance of streamline collective model on plane 流线集体模型在平面上减阻性能的数值模拟研究。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-02-01 DOI: 10.1140/epje/s10189-025-00473-8

Guanghao Li, Gongbo Li, Xin Fang, Guijie Liu

{"title":"Numerical simulation study on drag reduction performance of streamline collective model on plane","authors":"Guanghao Li, Gongbo Li, Xin Fang, Guijie Liu","doi":"10.1140/epje/s10189-025-00473-8","DOIUrl":"10.1140/epje/s10189-025-00473-8","url":null,"abstract":"<div><p>The energy carried by underwater vehicles is primarily employed to overcome water resistance. Reducing resistance can significantly enhance the speed and endurance of underwater vehicles. This study draws inspiration from biomimicry principles and proposes a novel drag reduction method inspired by the structural dynamics of fish schools. Building upon the structure of fish school, a collective model of streamlined forms is established. These streamlined collective models are arranged on a plane, and the study investigates the impact of various streamlined collective structures on planar resistance. By changing the spacing of the streamline collective model and flow field velocity, the drag reduction rules of different models at different flow rates are obtained. Through flow field analysis, the mechanism through which streamlined collective models achieve drag reduction on a flat surface is revealed. The research indicates that the streamlined collective models reduce total resistance by diminishing the viscous drag on the flat plate. The drag reduction effect generally decreases and then increases as the lateral spacing of the streamlined collective model increases. The maximum drag reduction rate can reach up to 8.63%. This study provides a novel approach for drag reduction in underwater vehicles, paving the way for further exploration and application development in this field.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vertex-based parameters of hierarchal lattice tube with an application of metric dimension 基于顶点的分层格管参数与度量维数的应用。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-28 DOI: 10.1140/epje/s10189-025-00471-w

Khawlah Alhulwah, Ali N. A. Koam, Nasreen Almohanna, Ali Ahmad, Muhammad Azeem

引用次数: 0

Microstructure response of concentrated suspensions to flow reversal 浓悬液的微观结构对回流的响应。

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-24 DOI: 10.1140/epje/s10189-025-00472-9

A. A. García, Y. L. Roht, I. Ippolito, D. Salin, G. Drazer, J. P. Hulin, G. Gauthier

{"title":"Microstructure response of concentrated suspensions to flow reversal","authors":"A. A. García, Y. L. Roht, I. Ippolito, D. Salin, G. Drazer, J. P. Hulin, G. Gauthier","doi":"10.1140/epje/s10189-025-00472-9","DOIUrl":"10.1140/epje/s10189-025-00472-9","url":null,"abstract":"<p>We study experimentally at the macroscopic and microstructure scale a dense suspension of non-Brownian neutrally buoyant spherical particles experiencing periodic reversals of flow at constant rate between parallel plates and tracked individually. We first characterize the quasi-steady state reached at the end of half periods. The volume fraction of particles increases from the walls to the center as a result of migration induced by the nonuniform strain rate. Except very close to the walls and the center, the particle pair distribution is fore-aft asymmetric with depletions of pairs in the extensional quadrants, similar to that reported for shear flows of same volume fraction as the local one. The dynamics of the periodic rearrangements occurring after each flow reversal are characterized by a microstructure tensor component. The relaxation time characterizing the reorganization increases from the walls to the center due to the inhomogeneous strain rate. On the other hand, the local accumulated strain required for this reorganization decreases with the volume fraction, like for viscosity measurements in uniform strain rate conditions. However, the variation of the microstructure with the accumulated strain is faster than that of the viscosity, showing the complementarity of the two measurements.</p><p>Left: Experimental image showing the particle suspension inside a slice of the channel. Middle: Representation of a pair of particles and its relative position vector. Right: Pair distribution function by the end of an oscillation</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of a liquid drop on a soft substrate 软基板上液滴的模拟

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-21 DOI: 10.1140/epje/s10189-024-00470-3

Yalda Poorhoshyar, Amir H. Fatollahi, Amir Aghamohammadi

{"title":"Simulation of a liquid drop on a soft substrate","authors":"Yalda Poorhoshyar, Amir H. Fatollahi, Amir Aghamohammadi","doi":"10.1140/epje/s10189-024-00470-3","DOIUrl":"10.1140/epje/s10189-024-00470-3","url":null,"abstract":"<p>A liquid drop resting on a soft substrate is numerically simulated as an energy minimization problem. The elastic substrate is modeled as a cubic lattice of mass-springs, to which an energy term controlling the change of volume is associated. The interfacial energy between three phases of solid, liquid, and vapor is also introduced. Under the constant volume constraint of the liquid drop, the total energy of the system is subjected to a numerical minimization process by which profiles of both substrate and drop are obtained. The numerical simulation enables the modeling of the wetting setup with various parameters associated with solid and liquid phases, including the Young’s modulus and Poisson’s ratio of the solid, the surface tension of the three phases, and geometrical parameters such as the contact radius or thickness of the solid. The direct outputs of the minimization process are the displacements of the solid lattice and boundary points of the liquid, by which the behavior of all relevant quantities, such as contact angles in the three phases, as well as the effective surface tension of the solid, can be quantitatively studied. The resulting displacements of the solid are compared with the exact solution of the elasticity equation under the assumption of no tangential traction, and a quite satisfactory agreement is observed. However, at larger Young’s modulus or lower Poisson’s ratios the agreement between the numerical results and the analytical solutions is lost in the vicinity of the contact points. Interestingly, a non-zero tangential traction in the vicinity of contact points is calculated by the numerical outputs, indicating that the assumption of zero tangential traction is not valid generally around the contact points. The effective surface tension at the contact points is calculated for an incompressible solid substrate, showing a linear increase with respect to the Young’s modulus of the solid, as <span>(delta gamma =c,E)</span>.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structural analysis of physical gel networks using graph neural networks 用图神经网络分析物理凝胶网络的结构

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-13 DOI: 10.1140/epje/s10189-024-00469-w

Matthias Gimperlein, Felix Dominsky, Michael Schmiedeberg

{"title":"Structural analysis of physical gel networks using graph neural networks","authors":"Matthias Gimperlein, Felix Dominsky, Michael Schmiedeberg","doi":"10.1140/epje/s10189-024-00469-w","DOIUrl":"10.1140/epje/s10189-024-00469-w","url":null,"abstract":"<p>We employ graph neural networks (GNN) to analyse and classify physical gel networks obtained from Brownian dynamics simulations of particles with competing attractive and repulsive interactions. Conventionally such gels are characterized by their position in a state diagram spanned by the packing fraction and the strength of the attraction. Gel networks at different regions of such a state diagram are qualitatively different although structural differences are subtile while dynamical properties are more pronounced. However, using graph classification the GNN is capable of positioning complete or partial snapshots of such gel networks at the correct position in the state diagram based on purely structural input. Furthermore, we demonstrate that not only supervised learning but also unsupervised learning can be used successfully. Therefore, the small structural differences are sufficient to classify the gel networks. Even the trend of data from experiments with different salt concentrations is classified correctly if the GNN was only trained with simulation data. Finally, GNNs are used to compute backbones of gel networks. As the node features used in the GNN are computed in linear time <span>(mathcal {O}(N))</span>, the use of GNN significantly accelerates the computation of reduced networks on a particle level.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00469-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simple method for the direct measurement of cohesive forces between microscopic particles 直接测量微观粒子间内聚力的简单方法

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-09 DOI: 10.1140/epje/s10189-024-00459-y

Johnathan Hoggarth, Kari Dalnoki-Veress

{"title":"Simple method for the direct measurement of cohesive forces between microscopic particles","authors":"Johnathan Hoggarth, Kari Dalnoki-Veress","doi":"10.1140/epje/s10189-024-00459-y","DOIUrl":"10.1140/epje/s10189-024-00459-y","url":null,"abstract":"<p>We present a simple and inexpensive method for measuring weak cohesive interactions. This technique is applied to the specific case of oil droplets with a depletion interaction, dispersed in an aqueous solution. The experimental setup involves creating a short string of droplets while immobilizing a single droplet. The droplets are held together via depletion interactions, and a single cohesive bond holds together nearest neighbours. Initially, the buoyant droplets are held in a flat horizontal chamber. The droplets float to the top of the chamber and are in contact with a flat glass interface. In the horizontal configuration, there is no component of the effective buoyant force acting in the plane of the chamber. The angle of the chamber is gradually increased, and the effective buoyant force acting on the string of droplets slowly increases. At a critical point, when the combination of gravity and buoyancy is equal to the cohesive force, the droplet string will detach from the immobile droplet. Our method allows for a simple direct measurement of cohesive forces on the tens of pico-Newton scale. To illustrate the validity of this technique, the droplet radii and concentration of depletant are varied, and their impact on the cohesive force is measured. This method offers a simple, accessible, and reproducible means of exploring cohesive interactions beyond the specific case of oil droplets and a depletion interaction.</p><p>(Top) Side and top-down view schematic of the experimental chamber. (Bottom) Stable and unstable dangling chain of droplets. The chain detaches from the stationary droplet once the effective buoyant force is greater than the cohesive force</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Weak non-linearities of amorphous polymer under creep in the vicinity of the glass transition 非晶聚合物在玻璃化转变附近蠕变的弱非线性

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-09 DOI: 10.1140/epje/s10189-024-00468-x

Martin Roman-Faure, Hélène Montes, François Lequeux, Antoine Chateauminois

{"title":"Weak non-linearities of amorphous polymer under creep in the vicinity of the glass transition","authors":"Martin Roman-Faure, Hélène Montes, François Lequeux, Antoine Chateauminois","doi":"10.1140/epje/s10189-024-00468-x","DOIUrl":"10.1140/epje/s10189-024-00468-x","url":null,"abstract":"<p>The creep behavior of an amorphous poly(etherimide) polymer is investigated in the vicinity of its glass transition in a weakly non linear regime where the acceleration of the creep response is driven by local configurational rearrangements. From the time shifts of the creep compliance curves under stresses from 1 to 15 MPa and in the temperature range between <span>(T_g -10K)</span> and <span>(T_g)</span>, where <span>(T_g)</span> is the glass transition temperature, we determine a macroscopic acceleration factor. The macroscopic acceleration is shown to vary as <span>(e^{-(Sigma /Y)})</span> temperature with <span>(n=2 pm 0.2)</span>, where <span>(Sigma )</span> is the macroscopic stress and <i>Y</i> is a decreasing function of compliance. Because at the beginning of creep, the stress is homogeneous, the macroscopic acceleration is thus similar to the local one, in agreement with the recent theory of Long et al. (Phys Rev Mat 2:105601, 2018) which predicts <span>(n=2)</span>. For larger compliances, the decrease of <i>Y</i> is interpreted as a signature of the development of stress disorder during creep.</p><p>Left: The acceleration of creep kinetics in a weakly non-linear regime in the vicinity of the glass transition is described through an acceleration function F which depends on both the applied stress and the compliance J(t) as a result of the stress induced shift of the relaxation time of nanometric domains (from top to bottom: increasing applied creep stresses). Right : Description of an amorphous polymer glass as a disordered medium made up of nanometric domains with widely distributed relaxation times.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142939051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extrinsic and intrinsic effects setting viscosity in complex fluids and life processes: the role of fundamental physical constants 复杂流体和生命过程中粘度的外在和内在影响：基本物理常数的作用

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-03 DOI: 10.1140/epje/s10189-024-00467-y

K. Trachenko, P. G. Tello, S. A. Kauffman, S. Succi

{"title":"Extrinsic and intrinsic effects setting viscosity in complex fluids and life processes: the role of fundamental physical constants","authors":"K. Trachenko, P. G. Tello, S. A. Kauffman, S. Succi","doi":"10.1140/epje/s10189-024-00467-y","DOIUrl":"10.1140/epje/s10189-024-00467-y","url":null,"abstract":"<p>Understanding the values and origin of fundamental physical constants, one of the grandest challenges in modern science, has been discussed in particle physics, astronomy and cosmology. More recently, it was realized that fundamental constants have a biofriendly window set by life processes involving motion and flow. This window is related to intrinsic fluid properties such as energy and length scales in condensed matter set by fundamental constants. Here, we discuss important extrinsic factors governing the viscosity of complex fluids operating in life processes due to collective effects. We show that both extrinsic and intrinsic factors affecting viscosity need to be taken into account when estimating the biofriendly range of fundamental constants from life processes, and our discussion provides a straightforward recipe for doing this. Remarkably, the viscosity of a complex fluid such as blood with significant extrinsic effects is not far from the intrinsic viscosity calculated using the fundamental constants only, and we discuss the reason for this in terms of dynamics of contact points between cells.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00467-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A hitchhiker’s guide to active motion 主动运动的搭便车指南

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2025-01-03 DOI: 10.1140/epje/s10189-024-00465-0

Tobias Plasczyk, Paul A. Monderkamp, Hartmut Löwen, René Wittmann

{"title":"A hitchhiker’s guide to active motion","authors":"Tobias Plasczyk, Paul A. Monderkamp, Hartmut Löwen, René Wittmann","doi":"10.1140/epje/s10189-024-00465-0","DOIUrl":"10.1140/epje/s10189-024-00465-0","url":null,"abstract":"<p>Intelligent decisions in response to external informative input can allow organisms to achieve their biological goals while spending very little of their own resources. In this paper, we develop and study a minimal model for a navigational task, performed by an otherwise completely motorless particle that possesses the ability of <i>hitchhiking</i> in a bath of active Brownian particles (ABPs). Hitchhiking refers to identifying and attaching to suitable surrounding bath particles. Using a reinforcement learning algorithm, such an agent, which we refer to as intelligent hitchhiking particle (IHP), is enabled to persistently navigate in the desired direction. This relatively simple IHP can also anticipate and react to characteristic motion patterns of their hosts, which we exemplify for a bath of chiral ABPs (cABPs). To demonstrate that the persistent motion of the IHP will outperform that of the bath particles in view of long-time ballistic motion, we calculate the mean-squared displacement and discuss its dependence on the density and persistence time of the bath ABPs by means of an analytic model.</p><p>Illustration of an intelligent hitchhiking particle (IHP) in a bath of active Brownian particles (ABPs). The IHP fulfills a navigational task by holding on to an ABP only if its orientation points upwards, enabling persistent motion.</p>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epje/s10189-024-00465-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142912970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bifurcation analysis and control of the full velocity difference model with delayed velocity difference 时滞速度差全速度差模型的分岔分析与控制

IF 1.8 4区物理与天体物理

The European Physical Journal E Pub Date : 2024-12-08 DOI: 10.1140/epje/s10189-024-00462-3

Wenhuan Ai, Guoao Li, Jianhua Zhang, Xiaoshuang Zhu, Dawei Liu

{"title":"Bifurcation analysis and control of the full velocity difference model with delayed velocity difference","authors":"Wenhuan Ai, Guoao Li, Jianhua Zhang, Xiaoshuang Zhu, Dawei Liu","doi":"10.1140/epje/s10189-024-00462-3","DOIUrl":"10.1140/epje/s10189-024-00462-3","url":null,"abstract":"<div><p>With the increase in the number of urban vehicles, various traffic problems have gradually emerged. Studying the causes of traffic congestion and proposing effective mitigation strategies have important practical significance. This paper proposes a macroscopic traffic flow model that considers the delayed speed difference. This paper applies nonlinear bifurcation to describe and predict nonlinear traffic phenomena on highways from the perspective of global stability of the traffic system. By using the traveling wave transformation, the proposed car-following model is converted into a macroscopic traffic flow model. Next, this paper employs the linear stability analysis to find the bifurcation points of the stability transition in the traffic system, exploring the qualitative characteristics of the inhomogeneous continuous traffic flow model. Theoretical derivations demonstrate the existence of bifurcation points within the model. Additionally, this paper plots the density-time space diagrams and phase plane diagrams of the system to visually present the sudden changes in traffic flow as variable parameters pass through these bifurcation points. Finally, this paper designs a feedback controller to regulate the Hopf bifurcation, aiming to delay or eliminate the occurrence of Hopf bifurcations in the stochastic system.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":790,"journal":{"name":"The European Physical Journal E","volume":"47 11","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0