Article
Engineering, Multidisciplinary
Babar Iftikhar, Muhammad Arshad Siddiqui, Tariq Javed
Summary: The study investigates the influence of a non-uniform magnetic field on heat transfer and entropy generation in the convection flow of ferrofluid. The governing equations are transformed into algebraic equations and solved using the Newton-Raphson method. Results show that increasing the magnetic number decreases fluid velocity and entropy generation. The intensity of streamlines decreases and velocity and temperature profiles increase with an increase in ferroparticle concentration.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Engineering, Multidisciplinary
S. Morteza Mousavi, A. Ali Rabienataj Darzi, Ming Li
Summary: This study numerically investigates the behavior of ferrofluids in the presence of neodymium block magnets, finding that the magnet significantly affects flow field and heat transfer, with the creation of secondary flow being more significant for low Reynolds numbers.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Multidisciplinary Sciences
Pradeep Kumar, Basavarajappa Nagaraja, Felicita Almeida, Abbani Ramakrishnappa AjayKumar, Qasem Al-Mdallal, Fahd Jarad
Summary: This study numerically simulates the time-based unsteady flow of Casson-Williamson nanofluid over a magnetic dipole enabled curved stretching sheet, considering factors such as thermal radiation, Joule heating, an exponential heat source, homo-heterogenic reactions, slip, and melting heat peripheral conditions. The analysis shows that the thermal buoyancy component enhances the velocity regime, while the melting parameter and radiation parameter have counterintuitive effects on the thermal profile. The ferrohydrodynamic interaction parameter slows down the velocity distribution of the nanofluid flow. Graphical representations of streamlines and isotherms are provided to demonstrate the flow and heat distribution.
SCIENTIFIC REPORTS
(2023)
Article
Green & Sustainable Science & Technology
A. Dahmani, J. Munoz-Camara, S. Laouedj, J. P. Solano
Summary: This study analyzes a novel configuration for heat transfer enhancement in parabolic trough solar collector absorbers using a ferrofluid and an external magnetic field. Results show that the periodic wire configuration can increase the Nusselt number and friction factor, leading to improved heat transfer efficiency.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2022)
Article
Thermodynamics
I Pishkar, B. Ghasemi, A. Raisi, S. M. Aminossadati
Summary: The natural convective heat transfer of Fe3O4/graphite slurry in a square cavity under a variable external magnetic field is numerically examined in this study. The results show that the position and magnetic number have a significant impact on the heat transfer performance, with enhanced heat transfer observed when the magnetic field source is located below the enclosure and near the heat source.
JOURNAL OF APPLIED FLUID MECHANICS
(2022)
Article
Physics, Multidisciplinary
Olalekan Adebayo Olayemi, Adebowale Martins Obalalu, Christopher Bode Odetunde, Olusegun Adebayo Ajala
Summary: This article investigates the flow of water-based Fe3O4 and Mn-ZnFe2O4 nanofluids between parallel stretchable spinning discs and examines the influence of rotational viscosity and applied magnetic field on the flow. It is found that the ferromagnetic Fe3O4 nanofluid shows higher thermal conductivity strength compared to the ferromagnetic Mn-ZnFe2O4 nanoparticles.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Physics, Fluids & Plasmas
Jahangir Alam, Ghulam Murtaza, Efstratios Tzirtzilakis, Mohammad Ferdows
Summary: The study investigates the biomagnetic flow and heat transfer of an incompressible electrically conductive fluid containing gold nanoparticles over a stretching sheet in the presence of a magnetic dipole, utilizing principles of MHD and FHD. Various parameters such as ferromagnetic parameter, magnetic field parameter, Grashof number, Eckert number, suction parameter, Biot number, slip parameter and Prandtl number were analyzed numerically and represented graphically. Results show that an increase in ferromagnetic parameter and Prandtl number leads to a decrease in velocity and temperature, respectively, with comparisons made to other literature results for certain parameter values.
Article
Engineering, Multidisciplinary
Iskander Tlili, S. P. Samrat, N. Sandeep, Hossam A. Nabwey
Summary: A computational framework was used to study the drive and thermal transport of unstable MHD Oldroyd-B ferrofluid flow with CoFe2O4 nanoparticles in water. Results showed that spherical ferrous particles have higher energy transport efficiency compared to tube and laminar shaped particles, and the Nusselt number can be regulated by the Deborah number and unsteadiness parameter.
AIN SHAMS ENGINEERING JOURNAL
(2021)
Article
Mathematics
Jahangir Alam, Ghulam Murtaza, Eugenia N. Petropoulou, Efstratios Em Tzirtzilakis, Mohammad Ferdows
Summary: In this study, the flow and heat characteristics of an unsteady, laminar biomagnetic fluid containing Fe3O4 magnetic particles under thermal radiation and a magnetic dipole influence were investigated using a group theory method. The mathematical formulation of the problem was constructed using biomagnetic fluid dynamics (BFD) principles. It was found that the fluid velocity is enhanced for increasing ferromagnetic number, while the temperature profile is decreased. The cylindrical shape of magnetic particles leads to a higher fluid temperature compared to the spherical shape. Moreover, the heat transfer rate of blood-Fe3O4 is significantly increased compared to pure blood, while the skin friction coefficient is reduced.
Article
Thermodynamics
Abdelraheem M. Aly, Sameh Elsayed Ahmed, Zehba Raizah
Summary: This paper aims to study unsteady ferrofluid flow with a hot source helix inside a cavity under the impacts of a variable magnetic field using incompressible smoothed particle hydrodynamics method. The research investigated different locations of a variable magnetic source outside the geometry. The findings showed that increasing the length of a helix by 0.4 resulted in a 25.60% reduction of the stream function.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2021)
Article
Mechanics
Aaiza Gul, Efstratios E. Tzirtzilakis, Stanislav S. Makhanov
Summary: This study presents a computational model for optimized magnetic navigation of magnetic nanoparticles coated with anticancer drugs inside blood vessels, utilizing two-way coupled momentum and temperature equations. The model, validated by experiments, has been applied to analyze vortex formation related to magnetic and drag forces, as well as characteristics of targeted magnetic drug delivery (TMDD) zones. The model has been verified against existing models and experimental data, showing that magnetohydrodynamics slows down blood flow and smooths vortices created by Ferrohydrodynamics, with evaluations on the impact of drug-loaded nanoparticle size on blood velocity and temperature.
Article
Physics, Applied
Qingwen Dai, Hao Xu, Chenbo Ma, Wei Huang, Xiaolei Wang
Summary: Inspired by liquid bridge bearings, a ferrofluid (FF) bearing is proposed in this work. The bearing consists of two plates with FF sandwiched between them and a cylindrical magnet implanted in the lower plate to restrain and position the FF. The carrying capacity of the liquid bridge and FF bearing is tested and compared, and the results show that the FF bearing provides a higher maximum force and more stable supporting performance due to the magnetic field effect.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Mathematics, Applied
Mubbashar Nazeer, Farooq Hussain, M. Ijaz Khan, Qasiar Shahzad, Yu-Ming Chu, Seifedine Kadry
Summary: This study compares the Newtonian and non-Newtonian multiphase flows drifting through an inclined channel, highlighting the significant importance of non-Newtonian biphase flows over Newtonian biphase flows. The findings suggest that Jeffrey fluid is suitable for multiphase flows, and Hafnium particle suspension with Jeffrey fluid performs better than crystal-Jeffrey suspension. Additionally, the combination of Hafnium with non-Newtonian fluid is well-suited for mechanical purposes, especially in nuclear reactor coolant applications, with no prior comparative analysis reported in existing literature.
NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Applied
B. Nagaraja, A. R. Ajaykumar, A. Felicita, Pradeep Kumar, Rudraswamy Ng
Summary: In this study, the possibility of Casson-Williamson nanofluid flow over a magnetic dipole-enabled curved stretching sheet is considered. A non-Darcy-Forchheimer model with nonlinear thermal radiation, homo-heterogenic reactions, Joule heating, exponential heat propagation, suction/injection, and melting heat peripheral conditions is used. The complex partial differential equations are transformed into more manageable ordinary differential equations using similarity catalysts. The research demonstrates the effects of different parameters on velocity distribution and thermal profile, and presents the flow and temperature distribution using streamlines and isotherms.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Engineering, Electrical & Electronic
Marcin Szczech, Krzysztof Kogut
Summary: A ferrofluid ring is similar to a liquid O-ring seal and is used in various applications. The main problem is leakage due to pressure differences, which affects the volume of liquid ejected outside the ring region. This study investigates the influence of magnetic and rheological properties on the formation of leakage channels in a single fluid ring.
IEEE TRANSACTIONS ON MAGNETICS
(2023)
Article
Mechanics
E. E. Tzirtzilakis
Article
Multidisciplinary Sciences
Kyriaki-Evangelia Aslani, Lefteris Benos, Efstratios Tzirtzilakis, Ioannis E. Sarris
Article
Multidisciplinary Sciences
Md. Ghulam Murtaza, Efstratios Emmanouil Tzirtzilakis, Mohammad Ferdows
Article
Mathematics, Applied
M. Ferdows, M. G. Murtaza, E. E. Tzirtzilakis, Faris Alzahrani
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2020)
Article
Engineering, Electrical & Electronic
Mohammad Ferdows, Md Ghulam Murtaza, Jagadis Chandra Misra, Efstratios Em Tzirtzilakis, Faris Alzahrani
Summary: This study investigates the steady boundary layer flow and heat transfer of biomagnetic fluid over a stretching/shrinking sheet with prescribed surface heat flux under the influence of a magnetic dipole. It is found that dual solutions exist for certain values of parameters, and stability analysis demonstrates that the first solution is stable and physically valid, while the second solution is unstable.
INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS
(2021)
Article
Mechanics
K. E. Hoque, M. Ferdows, S. Sawall, E. E. Tzirtzilakis, M. A. Xenos
Summary: This study investigates the hemodynamic properties of different degrees of stenosis in coronary arteries using pulsatile heart flow simulations. The results demonstrate the relationship between hemodynamic factors and predict physiological computation in severe MCS conditions. Insights gained from this study enhance the understanding and improvement of pathophysiological assessment of MCS, and provide a visualization method for diagnosing coronary irregularities.
Article
Engineering, Multidisciplinary
Aaiza Gul, Efstratios E. Tzirtzilakis, Stanislav S. Makhanov
Summary: Targeted magnetic drug delivery (TMDD) is a promising approach for multimodal cancer therapy. This study introduces a two-way coupled model to overcome the drawbacks of existing models and explores the formation of vortices generated by magnetic and drag forces, as well as the impact of nanoparticle size and concentration on blood temperature.
ENGINEERING APPLICATIONS OF COMPUTATIONAL FLUID MECHANICS
(2022)
Article
Mechanics
K. E. Hoque, M. Ferdows, S. Sawall, E. E. Tzirtzilakis, M. A. Xenos
Summary: Computed tomography coronary angiography image-based noninvasive virtual fractional flow reserve (vFFR) is a key factor in diagnosing coronary plaque, with both 1D and 3D hemodynamic factors being used to determine the severity of coronary main arteries lesions. The study shows that the 1D computational results can be used to predict the severity of atherosclerotic plaque in clinical procedures.
Article
Mechanics
Aaiza Gul, Efstratios E. Tzirtzilakis, Stanislav S. Makhanov
Summary: This study presents a computational model for optimized magnetic navigation of magnetic nanoparticles coated with anticancer drugs inside blood vessels, utilizing two-way coupled momentum and temperature equations. The model, validated by experiments, has been applied to analyze vortex formation related to magnetic and drag forces, as well as characteristics of targeted magnetic drug delivery (TMDD) zones. The model has been verified against existing models and experimental data, showing that magnetohydrodynamics slows down blood flow and smooths vortices created by Ferrohydrodynamics, with evaluations on the impact of drug-loaded nanoparticle size on blood velocity and temperature.
Article
Chemistry, Inorganic & Nuclear
Mohammad Ferdows, Jahangir Alam, Ghulam Murtaza, Efstratios E. Tzirtzilakis, Shuyu Sun
Summary: The numerical investigation of biomagnetic fluid flow and heat transfer through an unsteady stretching/shrinking cylinder containing magnetic particles is studied in this manuscript. The results show that different factors have significant impacts on fluid velocity, skin friction and heat transfer rate. This study provides valuable insights into the characteristics of biomagnetic fluid motion and heat transfer.
Article
Computer Science, Interdisciplinary Applications
Jahangir Alam, M. G. Murtaza, E. E. Tzirtzilakis, M. Ferdows
Summary: In this study, the behavior of blood flow with magnetic particles through a two-dimensional stretching cylinder under the influence of a magnetic field is investigated numerically and theoretically. The results reveal that the blood flow can be controlled by employing a strong magnetic field, which has significant implications for medical applications.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2022)
Article
Mechanics
M. H. Faruk, M. Ferdows, E. E. Tzirtzilakis
Summary: Magnetic hyperthermia can be regulated in the blood by using magnetic nanoparticles and changing the nature of the magnetic field. This research examines the effects of uniform and non-uniform magnetic fields on bio-magnetic fluid and nano-bio-magnetic fluid under hyperthermia. The study shows that a uniform magnetic field increases temperature locally but decreases the overall temperature, while a non-uniform field decreases both local maximum and average blood temperature.
Article
Mathematics, Applied
M. G. Murtaza, Jahanara Begum, E. E. Tzirtzilakis, M. Ferdows
Summary: The present study focuses on the boundary layer flow and heat transfer of magnetohydrodynamics Cu-water nanofluid flow over an exponentially shrinking sheet. A mathematical model and computational analysis are conducted, considering the effects of thermal radiation and suction. The system of partial differential equations is transformed into a set of ordinary differential equations using exponential form of similarity variables. The influence of various physical parameters on velocity and temperature distributions, skin friction coefficient, and heat transfer rate is demonstrated using graphical representations. The results show that the addition of nanoparticles in the base fluid significantly increases the fluid temperature, and increasing magnetic field and radiation parameters enhance the temperature distribution. Conversely, the suction parameter and Prandtl number have an opposite effect. The heat transfer rate is accelerated by the Eckert number and Prandtl number, while the skin friction coefficient is affected by the thermal radiation parameter. The comparison with previous computational results shows a close agreement.
CONTEMPORARY MATHEMATICS
(2023)
Article
Mathematics
Jahangir Alam, Ghulam Murtaza, Eugenia N. Petropoulou, Efstratios Em Tzirtzilakis, Mohammad Ferdows
Summary: In this study, the flow and heat characteristics of an unsteady, laminar biomagnetic fluid containing Fe3O4 magnetic particles under thermal radiation and a magnetic dipole influence were investigated using a group theory method. The mathematical formulation of the problem was constructed using biomagnetic fluid dynamics (BFD) principles. It was found that the fluid velocity is enhanced for increasing ferromagnetic number, while the temperature profile is decreased. The cylindrical shape of magnetic particles leads to a higher fluid temperature compared to the spherical shape. Moreover, the heat transfer rate of blood-Fe3O4 is significantly increased compared to pure blood, while the skin friction coefficient is reduced.
Article
Physics, Fluids & Plasmas
Jahangir Alam, Ghulam Murtaza, Efstratios Tzirtzilakis, Mohammad Ferdows
Summary: The study investigates the biomagnetic flow and heat transfer of an incompressible electrically conductive fluid containing gold nanoparticles over a stretching sheet in the presence of a magnetic dipole, utilizing principles of MHD and FHD. Various parameters such as ferromagnetic parameter, magnetic field parameter, Grashof number, Eckert number, suction parameter, Biot number, slip parameter and Prandtl number were analyzed numerically and represented graphically. Results show that an increase in ferromagnetic parameter and Prandtl number leads to a decrease in velocity and temperature, respectively, with comparisons made to other literature results for certain parameter values.
Article
Mathematics, Applied
Melanie Kobras, Valerio Lucarini, Maarten H. P. Ambaum
Summary: In this study, a minimal dynamical system derived from the classical Phillips two-level model is introduced to investigate the interaction between eddies and mean flow. The study finds that the horizontal shape of the eddies can lead to three distinct dynamical regimes, and these regimes undergo transitions depending on the intensity of external baroclinic forcing. Additionally, the study provides insights into the continuous or discontinuous transitions of atmospheric properties between different regimes.
PHYSICA D-NONLINEAR PHENOMENA
(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
Mathematics, Applied
Julien Nespoulous, Guillaume Perrin, Christine Funfschilling, Christian Soize
Summary: This paper focuses on optimizing driver commands to limit energy consumption of trains under punctuality and security constraints. A four-step approach is proposed, involving simplified modeling, parameter identification, reformulation of the optimization problem, and using evolutionary algorithms. The challenge lies in integrating uncertainties into the optimization problem.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Alain Bourdier, Jean-Claude Diels, Hassen Ghalila, Olivier Delage
Summary: In this article, the influence of a turbulent atmosphere on the growth of modulational instability, which is the cause of multiple filamentation, is studied. It is found that considering the stochastic behavior of the refractive index leads to a decrease in the growth rate of this instability. Good qualitative agreement between analytical and numerical results is obtained.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Ling An, Liming Ling, Xiaoen Zhang
Summary: In this paper, an integrable fractional derivative nonlinear Schrodinger equation is proposed and a reconstruction formula of the solution is obtained by constructing an appropriate Riemann-Hilbert problem. The explicit fractional N-soliton solution and the rigorous verification of the fractional one-soliton solution are presented.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Marzia Bisi, Nadia Loy
Summary: This paper proposes and investigates general kinetic models with transition probabilities that can describe the simultaneous change of multiple microscopic states of the interacting agents. The mathematical properties of the kinetic model are proved, and the quasi-invariant asymptotic regime is studied and compared with other models. Numerical tests are performed to demonstrate the time evolution of distribution functions and macroscopic fields.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Carlos A. Pires, David Docquier, Stephane Vannitsem
Summary: This study presents a general theory for computing information transfers in nonlinear stochastic systems driven by deterministic forcings and additive and/or multiplicative noises. It extends the Liang-Kleeman framework of causality inference to nonlinear cases based on information transfer across system variables. The study introduces an effective method called the 'Causal Sensitivity Method' (CSM) for computing the rates of Shannon entropy transfer between selected causal and consequential variables. The CSM method is robust, cheaper, and less data-demanding than traditional methods, and it opens new perspectives on real-world applications.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Feiting Fan, Minzhi Wei
Summary: This paper focuses on the existence of periodic and solitary waves for a quintic Benjamin-Bona-Mahony (BBM) equation with distributed delay and diffused perturbation. By transforming the corresponding traveling wave equation into a three-dimensional dynamical system and applying geometric singular perturbation theory, the existence of periodic and solitary waves are established. The uniqueness of periodic waves and the monotonicity of wave speed are also analyzed.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Wangbo Luo, Yanxiang Zhao
Summary: We propose a generalized Ohta-Kawasaki model to study the nonlocal effect on pattern formation in binary systems with long-range interactions. In the 1D case, the model displays similar bubble patterns as the standard model, but Fourier analysis reveals that the optimal number of bubbles for the generalized model may have an upper bound.
PHYSICA D-NONLINEAR PHENOMENA
(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
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)
Article
Mathematics, Applied
Yuhang Zhu, Yinghao Zhao, Chaolin Song, Zeyu Wang
Summary: In this study, a novel approach called Time-Variant Reliability Updating (TVRU) is proposed, which integrates Kriging-based time-dependent reliability with parallel learning. This method enhances risk assessment in complex systems, showcasing exceptional efficiency and accuracy.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Chiara Cecilia Maiocchi, Valerio Lucarini, Andrey Gritsun, Yuzuru Sato
Summary: The predictability of weather and climate is influenced by the state-dependent nature of atmospheric systems. The presence of special atmospheric states, such as blockings, is associated with anomalous instability. Chaotic systems, like the attractor of the Lorenz '96 model, exhibit heterogeneity in their dynamical properties, including the number of unstable dimensions. The variability of unstable dimensions is linked to the presence of finite-time Lyapunov exponents that fluctuate around zero. These findings have implications for understanding the structural stability and behavior modeling of high-dimensional chaotic systems.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Christian Klein, Goksu Oruc
Summary: A numerical study on the fractional Camassa-Holm equations is conducted to construct smooth solitary waves and investigate their stability. The long-time behavior of solutions for general localized initial data from the Schwartz class of rapidly decreasing functions is also studied. Additionally, the appearance of dispersive shock waves is explored.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
Article
Mathematics, Applied
Vasily E. Tarasov
Summary: This paper extends the standard action principle and the first Noether theorem to consider the general form of nonlocality in time and describes dissipative and non-Lagrangian nonlinear systems. The general fractional calculus is used to handle a wide class of nonlocalities in time compared to the usual fractional calculus. The nonlocality is described by a pair of operator kernels belonging to the Luchko set. The non-holonomic variation equations of the Sedov type are used to describe the motion equations of a wide class of dissipative and non-Lagrangian systems. Additionally, the equations of motion are considered not only with general fractional derivatives but also with general fractional integrals. An application example is presented.
PHYSICA D-NONLINEAR PHENOMENA
(2024)
