Article
Thermodynamics
Fazal Haq, Kamal Shah, Thabet Abdeljawad
Summary: This article reviews periodic heat transfer through extended surfaces (fins). It presents a detailed study of heat transfer variations through different types of fins and summarizes the results of periodic heat transfer and flow in fins. The performance of extended surfaces is measured in terms of fin effectiveness and efficiency. The heat transfer process is controlled by three dimensionless parameters: frequency parameter (w), convectional fins parameter (N), and amplitude parameter (A). Examples demonstrate the performance and efficiency of fins, with rectangular fins being the most effective for heat transfer to extended surfaces.
Article
Mathematics, Applied
Matthias Hieber, Hideo Kozono, Anton Seyfert, Senjo Shimizu, Taku Yanagisawa
Summary: In this passage, the existence of weak solutions v of the stationary Navier-Stokes equations in an exterior domain of R3 are discussed, where the solutions must satisfy certain boundary conditions. The first task is to find an appropriate solenoidal extension b into the domain, with subsequent analysis on the behavior of v based on the characteristics of b.
CALCULUS OF VARIATIONS AND PARTIAL DIFFERENTIAL EQUATIONS
(2021)
Article
Physics, Fluids & Plasmas
Jean-Luc Garden, Michel Peyrard
Summary: This paper investigates the application of temperature modulated calorimetry in different situations and compares it with standard scanning calorimetry. The study reveals the importance of temperature modulated calorimetry in observing the heat capacity changes in non-equilibrium systems and glassy samples.
Article
Engineering, Multidisciplinary
A. J. A. Ramos, R. Kovacs, M. M. Freitas, D. S. Almeida Junior
Summary: The Guyer-Krumhansl heat equation has important practical applications in heat conduction problems and can effectively describe the thermal behavior of macroscale heterogeneous materials. It is a promising candidate to be the next standard model in engineering, but its mathematical properties need to be thoroughly investigated and understood. This paper presents the basic structure of the equation and focuses on its differences from the Fourier heat equation. Additionally, it proves the well-posedness of a specific initial and boundary value problem and investigates the stability of the solution using a finite difference approach.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Astronomy & Astrophysics
Hyeong-Chan Kim, Youngone Lee
Summary: In this study, we investigate the problem of heat conduction in general relativity using Carter's variational formulation. We express the creation rates of entropy and particles as combinations of temperature and chemical potential vorticities, and discover the dynamical role of the binormal parts in thermodynamic systems. The introduction of binormal parts allows for a physical ansatz describing the evolution of the whole thermodynamic system, and we propose a suitable ansatz based on the physical properties of thermal equilibrium systems. Additionally, we explore the stability of a thermodynamic system in a flat background and find the existence of new 'Klein' modes and less stringent stability requirements than those in the literature.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Materials Science, Multidisciplinary
Chuang Zhang, Dengke Ma, Manyu Shang, Xiao Wan, Jing-Tao Lu, Zhaoli Guo, Baowen Li, Nuo Yang
Summary: Hotspots in micro/nanoscale chips are a common occurrence, and it has been discovered that thermal conductivity is not constant in such homogeneous systems. Graded thermal conductivity is observed, even with a fixed system size. The mechanisms of phonon scattering are analyzed, and it is found that the graded thermal conductivity can be predicted as long as there is not enough phonon scattering, independent of material properties, dimensions, or system size.
MATERIALS TODAY PHYSICS
(2022)
Article
Thermodynamics
A. . J. A. . Ramos, L. G. R. Miranda, M. M. Freitas, R. Kovacs
Summary: In this paper, the authors revisit the Guyer-Krumhansl heat equation and show that by satisfying thermodynamic conditions and the maximum principle, the occurrence of negative temperatures can be avoided. The study further emphasizes the thermodynamic origin of heat equations and their compatibility with the second law, and explores two different approaches to determine the initial state in a thermodynamically compatible way. Computational simulations provide support for the findings.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Mathematics, Applied
Xuefeng Liu, Mitsuhiro T. Nakao, Shin'ichi Oishi
Summary: This paper proposes a computer-assisted method for verifying the existence of a solution to the stationary Navier-Stokes equation over general 3D domains. The method verifies the existence of the exact solution as the fixed point of the Newton iteration around the approximate solution through rigorous computation and error estimation. The explicit values of quantities required by applying the fixed-point theorem are obtained by utilizing newly developed quantitative error estimation for finite element solutions to boundary value problems and eigenvalue problems of the Stokes equation.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2022)
Article
Physics, Particles & Fields
S. Kruglov
Summary: This article investigates the critical behavior of magnetically charged AdS black holes based on rational non-linear electrodynamics (RNED) in an extended phase space. The cosmological constant is considered as thermodynamic pressure, and the black hole mass is identified with the chemical enthalpy. An analogy with the van der Walls liquid-gas system is found, and the critical exponents coincide with those of the van der Waals system. The thermodynamics of RNED-AdS black holes and phase transitions are studied, and new thermodynamic quantities conjugated to the non-linear parameter of RNED and magnetic charge are defined. The consistency of the first law of black hole thermodynamics and the Smarr formula is demonstrated.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Fluids & Plasmas
Lucianno Defaveri, Alexandre A. A. Almeida, Celia Anteneodo
Summary: This study investigates thermal rectification in a system composed of two different segments of particles coupled to thermal baths. The results demonstrate the possibility of optimizing rectification by adjusting the exponent mu in the power-law potential that couples the interfacial particles.
Article
Mathematics, Applied
Naman Bartwal, Shantanu Shahane, Somnath Roy, Surya Pratap Vanka
Summary: In this paper, a high accuracy meshless method is proposed for solving heat conduction problems in complex domains. The method uses domain decomposition and cloud-based interpolation of scattered data to achieve high accuracy. The algorithm is demonstrated to be accurate in several two and three dimensional problems with sharp discontinuity in thermal conductivity.
APPLIED MATHEMATICS AND COMPUTATION
(2023)
Article
Thermodynamics
Behzad Ahmadi, Sajjad Bigham
Summary: Polymer heat exchangers are cost-effective and lightweight thermal management solutions with antifouling and anti-corrosion properties, but suffer from poor thermal characteristics due to low thermal conductivities. This study examines the thermal performance of 3D-printed polymer heat exchangers with intricate internal geometries, including a lung-inspired design, across a range of thermal conductivities. Experimentally and numerically, it was determined that high thermal conductivity lung-inspired polymer heat exchangers offer high thermal duties at reduced pressure drops and high effectiveness.
APPLIED THERMAL ENGINEERING
(2022)
Article
Materials Science, Characterization & Testing
Vladimir P. Vavilov
Summary: By using advanced 3D modeling, this study describes the basic features of thermal nondestructive testing (TNDT) problems and analyzes subtle physical phenomena that have not been properly studied before.
NDT & E INTERNATIONAL
(2022)
Article
Engineering, Civil
J. C. Monge, J. L. Mantari, R. A. Arciniega
Summary: This paper investigates the three-dimensional bending solution of doubly-curved shells subjected to mechanical, thermal, and hygrothermal loads. The temperature profile through the shell is modeled using Fourier's heat conduction equation, while the hygro-thermal profile is determined using Fick's moisture diffusion law. The governing equations are solved using Navier closed form summations, and the thickness profile is discretized using Legendre's grid distribution and solved using the Differential Quadrature Method (DQM). Results for cylindrical, spherical panels, and rectangular plates are presented and compared with existing solutions in the literature.
ENGINEERING STRUCTURES
(2022)
Article
Engineering, Mechanical
Yuanya Zhang, Yu He, Yongjun Zhou, Meng Liu, Yanling Wang, Junya Yuan, Xuehu Men
Summary: The RGO/CNTs/MXene aerogel-epoxy composites (RCM-EP) were prepared using freeze drying and resin perfusion process, and the pore sizes and morphologies of RCM aerogel were regulated by changing MXene concentration. The mechanical properties and thermal behaviors of EP composites with RCM and dispersed fillers were investigated, showing that RCM-EP had better mechanical strength and thermal properties due to outstanding dispersion performance, interfacial bonding, and spatial thermal conductivity network. The incorporation of RCM aerogel reduced the wear rate and friction coefficient of EP, while improving the bearing capacity and inhibiting the accumulation of friction heat.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Mathematics, Applied
E. Barbera, C. Curro, G. Valenti
PHYSICA D-NONLINEAR PHENOMENA
(2015)
Article
Physics, Multidisciplinary
Giancarlo Consolo, Carmela Curro, Giovanna Valenti
Article
Physics, Multidisciplinary
Elvira Barbera, Francesca Brini
Article
Acoustics
Elvira Barbera, Giovanna Valenti
Article
Mathematics, Applied
Giancarlo Consolo, Carmela Curro, Giovanna Valenti
MATHEMATICAL METHODS IN THE APPLIED SCIENCES
(2020)
Article
Mathematical & Computational Biology
Elvira Barbera
INTERNATIONAL JOURNAL OF BIOMATHEMATICS
(2020)
Article
Engineering, Mechanical
Giancarlo Consolo, Giovanna Valenti
Summary: This study develops a theory for voltage-induced control of magnetic domain walls propagating along a magnetostrictive nanostrip. The impact of piezo-induced strains on the magnetoelastic field is analyzed, and explicit expressions for key features of domain-wall propagation are derived. Strategies for optimizing voltage-induced control through the selection of ceramic piezoelectric materials and the orientation of dielectric poling are proposed.
Article
Physics, Fluids & Plasmas
Giancarlo Consolo, Carmela Curro, Gabriele Grifo, Giovanna Valenti
Summary: In this work, the role of inertial effects in the dynamics of oscillatory periodic patterns in a two-species hyperbolic reaction-advection-diffusion system is investigated. Linear stability analysis and multiple-scale weakly nonlinear analysis are used to determine the conditions for wave instability and the equation governing the spatiotemporal evolution of pattern amplitude. The investigation reveals the presence of a cubic complex Ginzburg-Landau equation with coefficients dependent on inertial times, leading to intriguing consequences. The extended Klausmeier model is presented as an illustrative example, demonstrating how inertia affects the region of wave instability and modulates the key features of the coherent structures.
Article
Materials Science, Multidisciplinary
G. Consolo, G. Valenti, A. R. Safin, S. A. Nikitov, V Tyberkevich, A. Slavin
Summary: A theory of electrically controlled THz-frequency auto-oscillator based on a trilayer heterostructure has been developed, showing that the AFMR frequency and THz frequency generation depend on the total AFM anisotropy. Adjusting the parameters such as material selection, electric field direction and driving current can optimize the performance of the oscillator.
Article
Mathematics, Applied
G. Conslo, S. Federico, G. Valenti
Summary: This theoretical study investigates the impact of magnetoelastic effects on the properties exhibited by magnetic domain walls propagating along the major axis of a thin magnetostrictive nanostrip coupled with a thick piezoelectric actuator. The analysis is carried out using the extended Landau-Lifshitz-Gilbert equation to describe the spatio-temporal evolution of the local magnetization vector driven by magnetic fields and electric currents. The results provide an explicit expression of key features in both steady and precessional regimes, and a qualitative comparison with literature data is also presented.
RICERCHE DI MATEMATICA
(2021)
Article
Mathematics, Applied
Elvira Barbera, Francesca Brini
RICERCHE DI MATEMATICA
(2019)
Proceedings Paper
Thermodynamics
Elvira Barbera, Francesca Brini
NONEQUILIBRIUM THERMODYNAMICS AND STATISTICAL PHYSICS: FROM RATIONAL MODELING TO ITS APPLICATIONS
(2018)
Article
Multidisciplinary Sciences
Elvira Barbera, Francesca Brini
ATTI ACCADEMIA PELORITANA DEI PERICOLANTI-CLASSE DI SCIENZE FISICHE MATEMATICHE E NATURALI
(2017)
Article
Mathematics, Applied
E. Barbera, C. Curro, G. Valenti
RICERCHE DI MATEMATICA
(2017)
Article
Mathematical & Computational Biology
Elvira Barbera, Giancarlo Consolo, Giovanna Valenti
MATHEMATICAL BIOSCIENCES AND ENGINEERING
(2015)
