Article
Thermodynamics
Yunpeng Xue, Colin Stewart, David Kelly, David Campbell, Michael Gormley
Summary: This study experimentally investigates the free-falling annular flow in a vertical pipe with different inlets, which is important for the design of building drainage systems. The research reports on the development process of the film velocity and thickness along the vertical pipe, which agrees well with empirical predictions. The results also show that a Tee-junction inlet in the drainage system generates a higher and different entrainment profile.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Tianxiong Li, Fei Wen, Yingchun Wu, Botong Wen, Lei Wang, Jinxin Guo, Xuecheng Wu
Summary: This study investigates the structure of the flow field induced by a strut in a scramjet and its influence on flame stabilization. Experimental and numerical analyses reveal that the flow field exhibits features beneficial for flame stabilization, but the asymmetry of the flow poses a challenge to flame establishment.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Merav Arogeti, Eran Sher, Tali Bar-Kohany
Summary: This study provides a detailed exploration of the events that occur when a droplet hits a dry solid surface of various small sizes, with a focus on the deposition, receding breakup, and prompt splash phases. By utilizing non-dimensional analysis and graphical representation, the boundaries between different events are defined, and criteria for differentiation based on target-to-drop ratio, Reynolds, and Webber numbers are presented.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Thermodynamics
Paulius Vilkinis, Justas Sereika, Gediminas Skarbalius, Algis Dziugys, Nerijus Pedisius
Summary: In this study, the trapping capability of different shaped microcavities for microparticles is experimentally investigated. The relationship between flow structure and particle behavior is observed, providing guidelines for the optimal design of micro- and nanofluidic devices.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2024)
Article
Mathematics, Applied
Shu-hong Xue, Yun-yun Yang, Biao Feng, Hai-long Yu, Li Wang
Summary: This research focuses on the robustness of multiplex networks and proposes a new index to measure their stability under malicious attacks. The effectiveness of this method is verified in real multiplex networks.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mechanics
P. Roca Ramis de Ayreflor, A. Viudez
Summary: In this study, the inelastic interactions between a small, intense dipole and a weak, neutral monopole in two-dimensional flows are examined. It is found that dipoles with small size but large amplitude can cross and scatter off the neutral vortex, while leaving the vortex stable.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Xiao-Jie Huang, Kambiz Vafai
Summary: In this study, the flow dynamics and heat transfer characteristics in nanofluid-based natural convection with a porous perturbation were analyzed. The results showed that the thermal conductivity had a significant effect on the flow strength and heat transfer. When the thermal conductivity was very small, the flow was obstructed by the porous perturbation.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mechanics
Hoe D. Nguyen, Truong V. Vu, Nang X. Ho, Phan H. Nguyen, Anh D. Le
Summary: In this study, the thermal migration of a compound droplet attached to a horizontal substrate is numerically investigated. The results show that the size of the inner droplet, viscosity ratio, and static contact angle can influence the movement direction of the compound droplet.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mathematics, Applied
Yu Li, Boxiao Li
Summary: This paper studies the numerical solution of a class of Riesz space fractional telegraph equation. The equations are discretized using the fractional central difference scheme in the spatial direction and a fourth-order exponential Runge-Kutta method is chosen in the temporal direction. An efficient method for calculating the matrix exponent and matrix phi-function is proposed, improving the efficiency of the matrix functions calculation. Numerical experiments demonstrate the convergence order and effectiveness of the scheme.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Marco Berardi, Giovanni Girardi
Summary: This paper presents a novel approach to mathematically frame the concept of ecological memory of plant water stress in the context of root water uptake. A non-local sink term is used to model water absorption by roots, taking into account the memory effect. An integral equation is defined to model this memory effect, with the main objective of providing conditions for the existence and uniqueness of its solution. Tailored numerical methods are implemented and numerical simulations are provided.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Nguyen Thi Van Anh
Summary: This paper introduces and studies an optimal control problem for a new class of fractional differential quasi-hemivariational inequalities with nonlocal initial conditions and Clarke sub-differentials. The main tools used in this study are the theory of fractional calculus, the fixed point argument for condensing multimaps, and Balder's theorem. The solvability of abstract nonlocal fractional differential quasi-hemivariational inequalities is proven, followed by the demonstration of the existence of solutions to the associated optimal control problems.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mechanics
Yasmin Hengster, Martin Lellep, Julian Weigel, Matthew Bross, Johannes Bosbach, Daniel Schanz, Andreas Schroder, Florian Huhn, Matteo Novara, Daniel Garaboa Paz, Christian J. Kahler, Moritz Linkmann
Summary: Using curvature and torsion to describe Lagrangian trajectories provides insights into small and large time scales. Probability density functions (PDFs) of curvature and torsion were calculated for experimental Lagrangian trajectories in different flows, and were compared with experimental and numerical simulation results. The effect of anisotropy on geometry or tracer particle trajectories was quantified using the curvature vector, which was found to be related to velocity fluctuations.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mathematics, Applied
Xing Zhang, Yongqiang Liu, Shaopu Yang, Weidong Niu, Yanhong Chen, Tao Guo
Summary: This paper studies the first passage problem of a wheelset system under Gaussian white noise excitation. The influence of noise intensity on mean first passage time and the sensitivity of yaw damper to the wheelset system at different operating speeds are analyzed. The paper also proposes the stochastic averaging method of quasi-non-integrable Hamiltonian system and approximates the Hamiltonian function as a one-dimensional Markov diffusion process dominated by Ito equation. The global stability of the wheelset system is analyzed using singular boundary theory, and the instability condition and critical speed are determined through theoretical analysis and numerical simulation.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Wenming Yang, Jiantuo Ren, Yifan Li, Beiying Liu
Summary: This study focuses on modeling the shape deformation and secondary flows in ferrofluid seals, using a combination of boundary element method and finite volume method. Numerical tests confirm the validity and accuracy of the proposed solution method. The results show that increasing the rotational speed of the shaft leads to deformation of the ferrofluid ring shape and reduces the contact area, resulting in a decrease in pressure resistance.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Piotr Bartman, Anna Ochal, Mircea Sofonea
Summary: This article considers a mathematical model that describes the quasistatic frictionless contact between a viscoelastic body and a rigid-plastic foundation. It discusses the mechanical assumptions and hypotheses on the data, and provides three different variational formulations with different unknowns. Furthermore, it proves that these formulations are dual to each other and deduces the unique weak solvability of the contact problem and the Lipschitz continuity of its weak solution with respect to the data. The proofs are based on recent results on history-dependent variational inequalities and inclusions. Finally, numerical simulations are presented along with corresponding mechanical interpretations to study the contact problem.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mechanics
Idalia Jagodzinska, Bartosz Olszanski, Konrad Gumowski, Slawomir Kubacki
Summary: This study investigates the characteristics of high subsonic and transonic flows through a linear cascade using experimental investigations and numerical simulations. The experiments measured static pressure, flow field, and turbulent intensity, and provided inlet conditions for the numerical simulations. The simulations validated the experimental data and tested the applicability of the turbulence models.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2024)
Article
Mathematics, Applied
X. Su, H. Zhang, C. Luo, L. Xu, S. Alghamdi
Summary: The paper investigates the controllability of generalized asynchronous Boolean networks under periodical impulsive control, transforming them into linear representations. Three different control modes are used to define controllability, providing reachable sets and calculable state transitions.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Corentin Correia, Ana Cristina Moreira Freitas, Jorge Milhazes Freitas
Summary: The emergence of clustering of rare events is due to periodicity, where fast returns to target sets lead to a bulk of high observations. In this research, we explore the potential of a new mechanism to create clustering of rare events by linking observable functions to a finite number of points belonging to the same orbit. We show that with the right choice of system and observable, any given cluster size distribution can be obtained.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Xin Li, Jin-Xuan Yang, Hai-Yan Wang, Ying Tan
Summary: Understanding network structure is crucial for controlling and mitigating the spread of infectious diseases. The authors developed an algorithm based on random walks to identify important links in social networks, which can effectively control the spread of infectious diseases.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2024)
Article
Mathematics, Applied
Enyu Fan, Changpin Li
Summary: This paper numerically studies the Allen-Cahn equations with different kinds of time fractional derivatives and investigates the influences of time derivatives on the solutions of the considered models.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
