Influence Of Magnetic Field Research Articles

Electrical Capacitors Based on Silicone Oil and Iron Oxide Microfibers: Effects of the Magnetic Field on the Electrical Susceptance and Conductance.

This paper presents the fabrication and characterization of plane capacitors utilizing magnetodielectric materials composed of magnetizable microfibers dispersed within a silicone oil matrix. The microfibers, with a mean diameter of about 0.94 μm, comprise hematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4). This study investigates the electrical behavior of these capacitors under the influence of an external magnetic field superimposed on a medium-frequency alternating electric field, across four distinct volume concentrations of microfibers. Electrical capacitance and resistance measurements were conducted every second over a 60-s interval, revealing significant dependencies on both the quantity of magnetizable phase and the applied magnetic flux density. Furthermore, the temporal stability of the capacitors' characteristics is demonstrated. The obtained data are analyzed to determine the electrical conductance and susceptance of the capacitors, elucidating their sensitivity to variations in microfiber concentration and magnetic field strength. To provide theoretical insight into the observed phenomena, a model based on dipolar approximations is proposed. This model effectively explains the underlying physical mechanisms governing the electrical properties of the capacitors. These findings offer valuable insights into the design and optimization of magnetodielectric-based capacitors for diverse applications in microelectronics and sensor technologies.

The Actuating Characteristics of Magnetorheological Fluids Subjected to Particle Sedimentation and Temperature Variation

Magnetorheological (MR) fluids are known for their controllable characteristics under the influence of magnetic fields and, hence, widely used as semi-active actuators for vibration control. Regardless of advantages such as fast response time and reversible property, MR fluids inevitably experience sedimentation caused by significant density mismatches between magnetic particles and carrier liquids. Moreover, the effect of the temperature on actuating characteristics is also one of the problems to be resolved for practical implementation. This study experimentally investigates the sedimentation behavior under various temperatures ranging from 25 to 70 °C using a multiguide-arm magnetic device that generates a uniform magnetic flux density across MR fluids. The sedimentation stability is then observed after 168 h at current inputs of 0, 1, and 2 A, respectively. Subsequently, the field-dependent rheological properties of MR fluids are evaluated using a rheometer and discussed, showing actuating capability, which depends on the viscosity, shear stress, and yield stress before (initial state) and after the sedimentation (sedimentation state). The field-dependent yield stresses, which directly represent the actuating force of the semi-active actuator, are specifically evaluated. Under the on-state condition (2 A) at a temperature of 70 °C, the yield stress decreased from 2.747 kPa (initial state) to 2.352 kPa (sedimentation state). By using this yield stress, the field-dependent damping force was evaluated, showing a decrement from 1672 N (initial state) to 1623 N (sedimentation state) at a velocity of 0.8 m/s. It is shown that the temperature causes the reduction of the actuating properties after the long-term operation. The insightful findings achieved in this work will provide useful information for the evaluation of actuating characteristics of smart MR fluids and the design of MR application systems subjected to particle sedimentation and temperature variation.

Numerical study on Fe3O4 nanoparticle separation from water flow using magnetic field: A 3D simulation

The development of magnetic separation technology using magnetic nanoparticles offers a promising avenue for targeted drug delivery and dealing with the upcoming water crises, environmental pollution and the gradual mineral resource depletion. In this study, a three-dimensional Lagrangian Discrete Phase Model (DPM) is carried out to simulate the performance of Fe3O4 nanoparticles to improve the separation process under the influence of an external magnetic field within a horizontal pipe. The crucial role of the drag force in capture efficiency (CE) prompted its examination, simulating various drag models for groups of particles. The Stokes-Cunningham model, showing a 3.59% average error is a suitable choice compared to experimental results. The research examines the impact of effective parameters, including flow velocity, magnetic field intensity, wire location, particle size and mass flow rate, and pipe diameter on CE and flow pattern. The results show that increasing nanoparticle concentration reshapes the flow pattern due to secondary flows without significantly changing separation efficiency. Moreover, decreasing flow velocity, diminishes drag force and enhances magnetic force impact. Specifically, reducing the velocity to a third increases CE by 37%. Furthermore, capture capacity varies approximately linearly with electric current. Due to the magnetic force’s role as a volumetric force in interphase momentum transfer, the increase in particle size from 200 to 500 nm at 3 × 105 A enhances CE by nearly 50%. However, increasing the pipe diameter diminishes particle capture, attributed to higher Reynolds numbers. According to the results, the impact of increasing magnetic field intensity and particle size on CE improvement is notably more pronounced compared to the effect of flow velocity reduction. A comparative analysis of three injection types reveals that using the group injection type helps to select an appropriate injection location to increase CE and identify the final positions of nanoparticles.

Weak magnetic effect and free radical reaction mechanism on the dissolution of lightweight magnesia in CaO–Al2O3–SiO2 melts

Lightweight magnesia-based refractories play a crucial role in achieving energy savings and carbon reduction in steelmaking furnaces. The primary requirement is to make lightweight magnesia refractories with high corrosion resistance. The introduction of a weak static magnetic field is also a promising way to improve the slag resistance of lightweight refractories in addition to optimizing the composition and structure of the refractories. In this paper, the dissolution behavior of the lightweight magnesia in CaO–Al2O3–SiO2 molten slags at and above 1600 °C under weak static magnetic field is presented. The influence of the weak static magnetic field on the dissolution rate was analyzed, the behavior from the perspective of free radical and kinetics was discussed, and the influence of different calcia–silica weight ratios (C/S) on slag, magnetic flux density and the reaction mechanism are revealed. The results show that the dissolution rate of the lightweight magnesia in the molten slag presents a significantly weak magnetic effect, with a reaction inhibition interval of 2–4 mT in the range of 0–16 mT magnetic field intensity, and the key inhibition threshold surpasses that of alumina. The mechanism of the free radical formation and reaction during magnesia dissolution in high-temperature slag is explained and illustrated. The relationship between the magnetic flux density, superoxide radical content, and dissolution rate is presented, providing theoretical guidance for developing magnetic combined magnesia refractories.

Numerical Simulation of a Parabolic Through Solar Collector with a Novel Geometric Design Equipped with an Elliptical Absorber Tube Under the Influence of Magnetic Field

Numerical Simulation of a Parabolic Through Solar Collector with a Novel Geometric Design Equipped with an Elliptical Absorber Tube Under the Influence of Magnetic Field

Magnetic field effects on electronic and optical properties in variant toroidal quantum ring: A comparative study of GaN, GaAs, and CdSe materials

In this work, we have examined the electronic and optical properties of three Variant Toroidal Quantum Ring (VTQR) materials, GaN, GaAs, and CdSe, in the presence of an axial magnetic field. Using an infinite potential model and based on the effective mass approximation, we calculated eigenvalues and eigenvectors using the three-dimensional finite difference method. This research aims to improve our understanding of the impact of the magnetic field on VTQRs of different sizes fabricated from various materials, such as GaAs, GaN, and CdSe. We simultaneously studied the geometrical parameters of VTQR nanostructures and the influence of the axial magnetic field on electronic energy, donor energy, electron-donor binding energy, magnetic shift, diamagnetic susceptibility, bandgap energy, and optical band gab. Our results show a strong correlation between electron-impurity binding energy, geometric parameters, and the presence of a magnetic field. CdSe consistently displays the highest binding energy, indicating superior stability under the study conditions. The effects of the magnetic field on these materials vary, with CdSe exhibiting increased sensitivity and GaAs demonstrating the lowest sensitivity. Nanostructure dimensions, including radii and curvature angles, play a central role in modulating the effects of binding energy and magnetic field, reflecting distinct electronic properties.

Health risks for medical personnel due to magnetic fields in magnetic resonance imaging.

The current state of medical and scientific knowledge on the effects of exposure to electromagnetic fields on workers in the field of clinical magnetic resonance imaging (MRI) is summarized here.A systematic literature search was conducted to analyze the health risks to medical personnel from magnetic fields in MRI. A total of 7273 sources were identified, with 7139 being excluded after screening of the title and abstract. After full-text screening, 34 sources remained and were included in this paper.There are a number of scientific publications on the occurrence of short-term sensory effects such as vertigo, metallic taste, phosphenes as well as on the occurrence of neurocognitive and neurobehavioral effects. For example, short-term exposure to clinical magnetic fields has been reported to result in a 4% reduction in speed and precision and a 16% reduction in visual contrast sensitivity at close range. Both eye-hand precision and coordination speed are affected. The long-term studies concern, among other things, the influence of magnetic fields on sleep quality, which could be linked to an increased risk of accidents. The data on the exposure of healthcare workers to magnetic fields during pregnancy is consistently outdated. However, it has been concluded that there are no particular deviations with regard to the duration of pregnancy, premature births, miscarriages, and birth weight. Epidemiological studies are lacking. With a focus on healthcare personnel, there is a considerable need for high-quality data, particularly on the consequences of long-term exposure to electromagnetic fields from clinical MRI and the effects on pregnancy. · Short-term sensory effects such as vertigo, metallic taste, phosphenes as well as neurocognitive and neurological behavioral effects may occur upon exposure to magnetic fields.. · Long-term effects mainly concern quality of sleep, which can be associated with an increased risk of accidents.. · When pregnant women were exposed to magnetic fields, no particular deviations were found with regard to the duration of pregnancy, premature births, miscarriages, and birth weight.. · König AM, Pöschke A, Mahnken AH. Health risks for medical personnel due to magnetic fields in magnetic resonance imaging. Fortschr Röntgenstr 2024; DOI 10.1055/a-2296-3860.

Melting and heat management of phase change material using smart ternary-hybrid coolant

This research investigates the effectiveness of using a smart ternary-hybrid nanofluid to enhance the melting rate and convective behavior of electrically conducting tin (Sn) in a rectangular enclosure under the influence of a uniform magnetic field. The enclosure has adiabatic vertical walls with hot and cold temperatures on the bottom and top walls. The finite element method (FEM) is used to solve the governing equations with appropriate boundary conditions using Galerkin's weighted residual approach. The study focuses on applying tin as the phase change material (PCM), with the highest temperature of 508 K, the lowest temperature of 503 K, and the melting interface temperature of 505 K. To enhance the heat transfer performance, tin-based ternary (graphene (G), silicon carbide (SiC), and nickel (Ni)) hybrid smart coolant is applied into the system. To investigate the mechanism of the melting and convective thermal transfer process, the results of the present study are reported with time for various values of the magnetic field (Ha) and solid concentration of ternary hybrid nanoparticle (ϕ). This study represents the streamlines, isothermal lines, melting interface, melting fraction, and heat transfer for the above-mentioned parameters. The results show that increasing the magnetic field reduces the rate of thermal transport by 38.96 % at t = 4000s. However, at a particular time of 2500s, increasing the solid volume fraction of nanoparticles enhances the melting fraction by approximately 8.34 %. Two regression equations are derived for the Nusselt number and melting fraction, with multiple response variables. This article improves understanding of natural convective heat transport during phase change processes for various coolants in different engineering applications.

A Fluid–Structure Interaction Analysis to Investigate the Influence of Magnetic Fields on Plaque Growth in Stenotic Bifurcated Arteries

A Fluid–Structure Interaction Analysis to Investigate the Influence of Magnetic Fields on Plaque Growth in Stenotic Bifurcated Arteries

Influence of a Constant Magnetic Field on the Parameters of the Magnetoplastic Effect in Aluminum Alloy B95pch

The present work is devoted to the comprehensive experimental study of the magnetoplastic effect found in the aluminum alloy B95pch aged in a weak constant magnetic field. The data on chemical composition of aluminum alloy B95pch, modes of thermal and thermomagnetic treatments and main experimentally observed regularities of changes in values of microhardness, modulus of elasticity of separate local areas and phase composition of aluminum alloy B95pch, aged at temperature 140°С, time from 2 to 8 h, in a constant magnetic field with intensity 557.0 kA/m and in its absence are presented. It was found that the constant magnetic field significantly affects the strength properties and structure of aluminum alloy B95pch. The negative magnetoplastic effect has been detected, the value of which is 21%. It is observed that the constant magnetic field does not significantly affect the average grain size, however, the size and number of observed foreign inclusions within the grain become significantly smaller compared to aging in the absence of magnetic field. In addition, the imposition of the constant magnetic field on the phase formation process leads to the formation of a more distorted structure: the half-width of diffraction lines becomes wider. The results of microhardness and modulus of elasticity measurements of aluminum alloy B95pc were found to be correlated.

Pulsed Magnetic Field Treatment Effects on Undissolved Carbides in Continuous Casting Billets of GCr15 Bearing Steel

The study investigates the effect of pulsed magnetic fields on undissolved carbides in high-carbon chromium bearing steel GCr15 billets. The billets were subjected to heat treatment at 950 °C, with a pulsed magnetic field of varying durations applied during the process. The influence of the pulsed magnetic field on the distribution of undissolved carbides within the billets was investigated, and the thermodynamic and kinetic mechanisms of undissolved carbides dissolution were explored. The results indicate that the area percentage of undissolved carbides in the microstructure decreases from 1.68% to 0.06% after applying a pulsed magnetic field for 10 min, and the size of undissolved carbides decreases from 17.5 μm to 4.9 μm. When a pulsed magnetic field is applied for 30 min, all undissolved carbides dissolve. The statistics demonstrate that the average size of undissolved carbides is reduced from 14.19 μm to 0.63 μm, with a reduction percentage reaching 96%. Over the same duration, the number density of the undissolved carbides decreases from (0.19~0.55)/mm2 to (0.03~0.1)/mm2, and the percentage area of the undissolved carbides decreases from (1.26~1.68)% to (0~0.02)%. Thermodynamically, applying a pulsed magnetic field lowers the dissolution energy barrier of undissolved carbides and modifies their transformation temperature. Kinetically, the rate of alloy element diffusion is enhanced by increasing the frequency of atomic jumps. This research aims to provide new insights into enhancing the contact fatigue life of bearing steel, increasing the proportion of special steel, and optimizing the steel deep-processing process.

Enhancement of the anomalous Hall effect by distorting the Kagome lattice in an antiferromagnetic material

In topological magnetic materials, the topology of the electronic wave function is strongly coupled to the structure of the magnetic order. In general, ferromagnetic Weyl semimetals generate a strong anomalous Hall conductivity (AHC) due to a large Berry curvature that scales with their magnetization. In contrast, a comparatively small AHC is observed in noncollinear antiferromagnets. We investigated HoAgGe, an antiferromagnetic (AFM) Kagome spin-ice compound, which crystallizes in a hexagonal ZrNiAl-type structure in which Ho atoms are arranged in a distorted Kagome lattice, forming an intermetallic Kagome spin-ice state in the ab-plane. It exhibits a large topological Hall resistivity of ~1.6 µΩ-cm at 2.0 K in a field of ~3 T owing to the noncoplanar structure. Interestingly, a total AHC of 2,800 Ω-1 cm-1 is observed at ~45 K, i.e., 4 TN, which is quite unusual and goes beyond the normal expectation considering HoAgGe as an AFM Kagome spin-ice compound with a TN of ~11 K. We demonstrate further that the AHC below TN results from the nonvanishing Berry curvature generated by the formation of Weyl points under the influence of the external magnetic field, while the skew scattering led by Kagome spins dominates above the TN. These results offer a unique opportunity to study frustration in AFM Kagome lattice compounds.

The magnetic field on the bioconvection flow of NEPCM in A Z-shaped cavity containing three circular cylinders

This work adopts an incompressible smoothed particle hydrodynamics (ISPH) method for handling the bioconvection flow of nanoparticle-enhanced phase change materials (NEPCM) inside a Z-shaped containing three circular cylinders and oxytactic microorganisms. The fractional time derivative of a system of controlling equations is solved by the ISPH method. The influences of magnetic field on thermosolutal convection of NEPCM in Z-shaped cavity. The mesh-free nature of the ISPH method helps in simulating the nanofluid flow in complex geometries. The Z-shaped cavity was chosen in this work for bioconvection flow because of its uses in semiconductors in solar cells, electronic devices, biomedicine, and thermal batteries. The bioconvection flow and heat transfer of the embedded circular cylinders are significant in heat exchangers and renewable energies. The scales of physical parameters are bioconvection Rayleigh number Rab=1−1000, Lewis number Le=1−20, Hartmann number Ha=0−80, fractional-time derivative α=0.9−1, Rayleigh number Ra=103−106, the radius of embedded circular cylinders Rc=0.05−0.2, and nanoparticles’ parameter ϕ=0−0.15. The results introduced the importance of Rab in enhancing the distributions of oxytactic microorganisms, and oxygen concentrations as well as the intensity of the velocity field. The size of embedded circular cylinders is effective in adjusting the distributions of oxytactic microorganisms, oxygen concentration, and temperature inside a Z-shaped cavity. The maximum velocity field decreases by 86.79 % as nanoparticle concentration increases from 0 % to 15 % due to the resulting high viscosity of the suspension fluid. An expanded radius of embedded circular cylinders improves the values of Nu‾ and Sh‾. This research provides crucial insights into optimizing thermal management and efficiency across diverse technological applications, from electronics to renewable energy and biomedical devices.

Investigation of MHD flow balancing in electrically conductive manifolds of liquid metal blankets

In the liquid metal (LM) blanket design for magnetic confinement fusion reactors, manifolds including main and branch ducts are commonly used to direct fluids to various locations of the blanket to cool its components. The primary objective of this structural configuration is to achieve flow balancing within each branch duct. However, magnetohydrodynamic effects will cause uneven flow distribution, consequently, uncontrollable overheating phenomena in certain blanket segments may be caused by this flow distribution. To assess its impact, the influences of external magnetic fields, inlet velocities and coupling wall thicknesses on the flow partitioning in conductive manifolds are investigated in this study. The results indicate that the flow distribution among the branch ducts becomes less uniform as the external magnetic field strength increases, while varying the inlet velocity has minimal impact. In addition, increasing the coupling wall thickness leads to more even flow distribution when the rectangular branch ducts are perpendicular with the magnetic field direction. Based on above physical understanding, three controlling methods for the flow partitioning in conductive manifolds are proposed to achieve flow balancing in each branch duct and then validated through numerical simulations. The results indicate that flow balancing can be achieved by adjusting the coupling wall thickness when the rectangular branch ducts are aligned with the magnetic field direction, however, it is challenging when they are perpendicular. Furthermore, the flow balancing can be realized by a symmetrical design of the manifold with circular branch pipes and it is independent of external magnetic fields and inlet velocities. These findings will enhance the physical understanding of flow distribution patterns in conductive manifolds under strong magnetic fields, which is important for the flow control and design of manifolds in LM blankets.

Two-Field Excitation for Contactless Inductive Flow Tomography.

Contactless inductive flow tomography (CIFT) is a flow measurement technique allowing for visualization of the global flow in electrically conducting fluids. The method is based on the principle of induction by motion: very weak induced magnetic fields arise from the fluid motion under the influence of a primary excitation magnetic field and can be measured precisely outside of the fluid volume. The structure of the causative flow field can be reconstructed from the induced magnetic field values by solving the according linear inverse problem using appropriate regularization methods. The concurrent use of more than one excitation magnetic field is necessary to fully reconstruct three-dimensional liquid metal flows. In our laboratory demonstrator experiment, we impose two excitation magnetic fields perpendicular to each other to a mechanically driven flow of the liquid metal alloy GaInSn. In the first approach, the excitation fields are multiplexed. Here, the temporal resolution of the measurement needs to be kept as high as possible. Consecutive application by multiplexing enables determining the flow structure in the liquid with a temporal resolution down to 3 s with the existing equipment. In another approach, we concurrently apply two sinusoidal excitation fields with different frequencies. The signals are disentangled on the basis of the lock-in principle, enabling a successful reconstruction of the liquid metal flow.

Magnetized AdS/BCFT Correspondence in Horndeski Gravity

AbstractThis work examines the thermodynamics and hydrodynamics behaviors of a five‐dimensional black hole under the influence of an external magnetic field. The solution is the gravity dual to the Anti‐de Sitter/Boundary Conformal Field Theory correspondence, enabling the study of properties within an anisotropic fluid framework. Utilizing holographic renormalization, the free energy and the holographic stress tensor residing on the boundary denoted as are computed. Within the fluid/gravity correspondence framework, authors have a class of boundary extensions in , where the stress‐energy tensor describes a magnetizing conformal fluid. The characteristics of this special solution as well as its thermodynamic properties, including the bulk and shear viscosity, the square of the speed of sound, as well as the anisotropic effects induced by the magnetic field in the magnetized conformal plasma are discussed.

Influence of the external magnetic field on structural characteristics of granular Co-Cu thin film alloys

We present the results of experimental studies of the influence of an external magnetic field on the structural characteristics (surface roughness and structural entropy) of nanogranular thin-film system based on Co and Cu. The samples CoxCu100-x in a wide range of compositions (17 at. % ≤ x ≤ 69 at. %) with the thickness of d = 35 nm were obtained by electron-beam co-evaporation using two independent electron guns. After obtaining, the films were annealed in a vacuum at a temperature of 800 K for 30 min. The studies of magnetoresistive properties have shown that the maximum giant magnetoresistance (GMR) amplitude (1.7 % in the transverse and 1.6 % in the longitudinal measurement geometries) in a magnetic field of H = 4.5 kOe at room temperature was observed in the Co21Cu79 film alloy. Transmission electron microscopy showed that this sample contains hcp-Co granules with a size of L = 5 ÷ 12 nm in a matrix of metastable fcc-Cu(Co) solid solution. The influence of the external magnetic field on the structural characteristics and surface morphology of the Co21Cu79 thin-film alloy was investigated using atomic force microscopy (AFM). It was found that a first impact of application of external magnetic field with H = 0.5 kOe causes a decrease in the values of the arithmetic mean Ra, and quadratic mean Rq, of the film roughness and structural entropy S. A decreases in Ra by 8.5 %, Rq by 6.5 %, and structural entropy S by 6.5 % were observed. After application of a larger magnetic field with H = 1.0 kOe and during the subsequent relaxation of the structure within 15 h after the field is turned off, the values of the structural parameters of the film surface did not change significantly.

A micromagnetic-mechanically coupled phase-field model for fracture and fatigue of magnetostrictive alloys

Magnetostrictive alloys are usually brittle materials with micromagnetic structures. Their structural reliability and durability depend on the complex micromagnetic-mechanical coupling at smaller length scales encompassing the evolution of micromagnetic structures. Herein we propose a micromagnetic-mechanically coupled phase-field model for fracture and fatigue behavior of magnetostrictive alloys with evolution of the micromagnetic structure. The thermodynamically-consistent model is derived from microforce theory, laws of thermodynamics, and Coleman–Noll analysis. The evolution of crack phase-field and magnetization-vector order parameters that are fully coupled is governed by history field dependent Allen–Cahn and Landau–Lifshitz–Gilbert equations, respectively. The model is extended to fatigue by introducing a degradation prefactor for the fracture energy as a function of positive elastic energy. One-dimensional analyses are then presented to anatomize the crack driving forces in terms of fully coupled micromagnetic-mechanical and pure mechanical driving force. We demonstrate the model capabilities by finite-element numerical studies on the micromagnetic domain evolution during the crack propagation and the influence of external magnetic field for type-I, type-II, and three-point bending fracture, as well as for the fracture of a single-edge notched specimen with an elliptical inclusion. The simulation result shows that depending on how micromagnetic domains are switched under micromagnetic-mechanical coupling, the magnetic field can enhance or decrease the critical load. In the presence of inclusion with larger fracture toughness, a crack is found to nucleate in the tri-junction of multi-domain micromagnetic structure owing to the high elastic strain around the tri-junction point. It is further found that a suitable magnetic field promoting magnetization-vector rotation around the crack tip could remarkably improve the fracturing load and fatigue life. The results demonstrate the model promising for the study of micromagnetic-mechanically coupled fracture and fatigue in magnetostrictive alloys.

Study on the influence of transverse magnetic field on the arc and reignition characteristics of HVDC relays

It is of great significance to clarify the influence of transverse magnetic field (TMF) on arc control in high-voltage direct current (HVDC) relays. In this paper, the influence of TMF in a wide range of 0–140 mT on the arc characteristics of HVDC relays is studied, the experimental observations of arc reignition are carried out and the effect of arc reignition on contact erosion, the criterion of arc reignition and the mechanism of TMF enhancement on arc reignition are further analyzed. The results show that the TMF enhancement is beneficial for shortening the arc voltage stagnation duration and accelerating the speed of arc elongation, arc dispersion and dispersed arc motion, thereby improving the arc extinguishing performance. However, higher TMF leads to more severe and earlier arc reignition, as also shown in the experimental observations. The arc reignition further causes a sudden drop in arc voltage, prolonged arc duration and uneven contact erosion. To evaluate the occurrence of arc reignition caused by TMF enhancement, a simplified breakdown criterion is proposed through the defined characteristic variable C¯(t) . Based on this, the mechanism by which the TMF enhancement more easily causes arc reignition is explained, that is the higher TMF leads to an earlier and faster increase in C¯(t) and slightly reduces the breakdown threshold C¯∗(t5,D) . Further, measures to suppress the arc reignition are proposed.

On thermal non-equilibrium (TNE) model for heat transfer in ternary ferro-nanofluid with rectangular porous fin

The heat transmission in a rectangular porous fin affected by a thermal non-equilibrium model with radiation and magnetic field influences is studied in this study. A ferrofluid containing ferroparticles (Fe3O, CoFe2O4, and Cu) and a mixture of 50 % water and 50 % ethylene glycol coats the fin. Dimensionless form is later achieved by formulating the governing equations for both the solid and ferrofluid phases. In order to get the answer, the Runge–Kutta–Fehlberg (RK-45) scheme is used. Visual and tabular representations are used to investigate the effect on heat transmission of the Biot and Rayleigh numbers as well as the porous and convective parameters. The results show that the solid phase temperature profile is inferior for lower Hartmann numbers (H) and Rayleigh numbers (Ra). The disparity in temperature between the solid and ferrofluid phases decreases in proportion to the Ra. Applications for this type of device include heat exchangers, air conditioners, and cooling towers.