Kalidas Das and Pinaki Ranjan Duari
Several graphs, streamlines, isotherms and 3D plots are illustrated to enlighten the noteworthy fallouts of the investigation. Embedding flow factors for velocity, induced magnetic…
Abstract
Purpose
Several graphs, streamlines, isotherms and 3D plots are illustrated to enlighten the noteworthy fallouts of the investigation. Embedding flow factors for velocity, induced magnetic field and temperature have been determined using parametric analysis.
Design/methodology/approach
Ternary hybrid nanofluids has outstanding hydrothermal performance compared to classical mono nanofluids and hybrid nanofluids owing to the presence of triple tiny metallic particles. Ternary hybrid nanofluids are considered as most promising candidates in solar energy, heat exchangers, electronics cooling, automotive cooling, nuclear reactors, automobile, aerospace, biomedical devices, food processing etc. In this work, a ternary hybrid nanofluid flow that contains metallic nanoparticles over a wedge under the prevalence of solar radiating heat, induced magnetic field and the shape factor of nanoparticles is considered. A ternary hybrid nanofluid is synthesized by dispersing iron oxide (Fe3O4), silver (Ag) and magnesium oxide (MgO) nanoparticles in a water (H2O) base fluid. By employing similarity transformations, we can convert the governing equations into ordinary differential equations and then solve numerically by using the Runge–Kutta–Fehlberg approach.
Findings
There is no fund for the research work.
Social implications
This kind of study may be used to improve the performance of solar collectors, solar energy and solar cells.
Originality/value
This investigation unfolds the hydrothermal changes of radiative water-based Fe3O4-Ag-MgO-H2O ternary hybrid nanofluidic transport past a static and moving wedge in the presence of solar radiating heating and induced magnetic fields. The shape factor of nanoparticles has been considered in this study.
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The purpose of this paper is to investigate yoyo potential difference and induction of electric yoyo flows by using the general systemic yoyo model and available quantitative…
Abstract
Purpose
The purpose of this paper is to investigate yoyo potential difference and induction of electric yoyo flows by using the general systemic yoyo model and available quantitative tools.
Design/methodology/approach
Empirical laws and well‐known laboratory experiments of physics are revisited in light of the spinning yoyo method and thinking logic. When appropriate, relevant quantitative methods are established.
Findings
By generalizing the concept of electromotive force, the paper introduces that of meridian motive forces (MMF). By considering two possible cases when electric yoyo flows can be induced within a return circuit, the paper uses specific examples to compute yoyo potential differences, the forces needed to pull a conductive wire in a magnetic yoyo field, and the total flux of magnetic yoyo field passing through a return circuit. When the paper tries to address the questions of how an electric yoyo current in a circuit is produced and what force could get around the resistance of metals to make electric yoyo charges move around inside return circuits, the paper successfully establishes a theoretical explanation for why Lenz's law about the direction of induced electric currents holds true. At the end, the paper develops a quantitative formula for practically calculating desired MMF.
Originality/value
This paper provides the first ever theoretical explanation for why Lenz's law could be true. It is expected that this explanation would be equally applicable in the study of social systems.
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Hongbo Qiu, Wenfei Yu, Shuai Yuan, Bingxia Tang and Cunxiang Yang
The impact of the loop current (LC) on the motor magnetic field in the analysis of the inter-turn short circuit (ITSC) fault is always ignored. This paper made a comparative study…
Abstract
Purpose
The impact of the loop current (LC) on the motor magnetic field in the analysis of the inter-turn short circuit (ITSC) fault is always ignored. This paper made a comparative study on the electromagnetic field of permanent magnet synchronous motors (PMSM). The purpose of this study is to explore the necessary of the LC existing in the fault analysis and the electromagnetic characteristics of the PMSM with the ITSC fault when taking into account the LC.
Design/methodology/approach
Based on the finite element method (FEM), the fault model was established, and the magnetic density of the fault condition was analyzed. The induced electromotive force (EMF) and the LC of the short circuit ring were studied. The three-phase induced EMF and the unbalance of the three-phase current under the fault condition were studied. Finally, a prototype test platform was built to obtain the data of the fault.
Findings
The influence of the fault on the magnetic density was obtained. The current phase lag when the ITSC fault occurs causes the magnetic enhancement of the armature reaction. The mechanism that LC hinders the flux change was revealed. The influence of the fault on the three-phase-induced EMF symmetry, the three-phase current balance and the loss was obtained.
Originality/value
The value of the LC in the short circuit ring and the influence of it on the motor electromagnetic field were obtained. On the basis of the electromagnetic field calculation model, the sensitivity of the LC to the magnetic density, induced EMF, current and loss were analyzed.
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R. Meenakumari, P. Lakshminarayana and K. Vajravelu
The aim of the present paper is to investigate the homogeneous and heterogeneous reactions on Prandtl fluid flow at a stretching sheet with an induced magnetic field and slip…
Abstract
Purpose
The aim of the present paper is to investigate the homogeneous and heterogeneous reactions on Prandtl fluid flow at a stretching sheet with an induced magnetic field and slip boundary conditions.
Design/methodology/approach
The governing equations include the continuity, induced magnetic field, momentum, energy and homogeneous–heterogeneous equations. Initially, with suitable similarity variables, the governing partial differential equations and converted into a system of ordinary differential equations. Then, the nonlinear ordinary differential equations are solved by a shooting technique with the help of the BVC5C Matlab package.
Findings
The results of the present investigation are presented through graphs for different values of the various parameters. The authors observed that the large values of the stretching ratio and the induced magnetic parameters are moderate magnetic field, velocity and temperature primarily. Also, the authors found the more velocity and temperatures by boosting the slip parameters.
Originality/value
In addition, the values of the skin friction and the rate of heat transfer for various values of physical parameters are tabulated and deliberated in detail.
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Chandan Kumawat, Bhupendra Kumar Sharma, Taseer Muhammad and Liaqat Ali
The purpose of this study is to determine the impact of two-phase power law nanofluid on a curved arterial blood flow under the presence of ovelapped stenosis. Over the past…
Abstract
Purpose
The purpose of this study is to determine the impact of two-phase power law nanofluid on a curved arterial blood flow under the presence of ovelapped stenosis. Over the past couple of decades, the percentage of deaths associated with blood vessel diseases has risen sharply to nearly one third of all fatalities. For vascular disease to be stopped in its tracks, it is essential to understand the vascular geometry and blood flow within the artery. In recent scenarios, because of higher thermal properties and the ability to move across stenosis and tumor cells, nanoparticles are becoming a more common and effective approach in treating cardiovascular diseases and cancer cells.
Design/methodology/approach
The present mathematical study investigates the blood flow behavior in the overlapped stenosed curved artery with cylinder shape catheter. The induced magnetic field and entropy generation for blood flow in the presence of a heat source, magnetic field and nanoparticle (Fe3O4) have been analyzed numerically. Blood is considered in artery as two-phases: core and plasma region. Power-law fluid has been considered for core region fluid, whereas Newtonian fluid is considered in the plasma region. Strongly implicit Stone’s method has been considered to solve the system of nonlinear partial differential equations (PDE’s) with 10–6 tolerance error.
Findings
The influence of various parameters has been discussed graphically. This study concludes that arterial curvature increases the probability of atherosclerosis deposition, while using an external heating source flow temperature and entropy production. In addition, if the thermal treatment procedure is carried out inside a magnetic field, it will aid in controlling blood flow velocity.
Originality/value
The findings of this computational analysis hold great significance for clinical researchers and biologists, as they offer the ability to anticipate the occurrence of endothelial cell injury and plaque accumulation in curved arteries with specific wall shear stress patterns. Consequently, these insights may contribute to the potential alleviation of the severity of these illnesses. Furthermore, the application of nanoparticles and external heat sources in the discipline of blood circulation has potential in the medically healing of illness conditions such as stenosis, cancer cells and muscular discomfort through the usage of beneficial effects.
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Yang Zhou, Wenying Qu, Fan Zhou, Xinggang Li, Lijun Song and Qiang Zhu
This paper aims to understand the magnetohydrodynamics (MHD) mechanism in the molten pool under different modes of magnetic field. The comparison focuses on the Lorenz force…
Abstract
Purpose
This paper aims to understand the magnetohydrodynamics (MHD) mechanism in the molten pool under different modes of magnetic field. The comparison focuses on the Lorenz force excitation and its effect on the melt flow and solidification parameters, intending to obtain practical references for the design of magnetic field-assisted laser directed energy deposition (L-DED) equipment.
Design/methodology/approach
A three-dimensional transient multi-physical model, coupled with MHD and thermodynamic, was established. The dimension and microstructure of the molten pool under a 0T magnetic field was used as a benchmark for accuracy verification. The interaction between the melt flow and the Lorenz force is compared under a static magnetic field in the X-, Y- and Z-directions, and also an oscillating and alternating magnetic field.
Findings
The numerical results indicate that the chaotic fluctuation of melt flow trends to stable under the magnetostatic field, while a periodically oscillating melt flow could be obtained by applying a nonstatic magnetic field. The Y and Z directional applied magnetostatic field shows the effective damping effect, while the two nonstatic magnetic fields discussed in this paper have almost the same effect on melt flow. Since the heat transfer inside the molten pool is dominated by convection, the application of a magnetic field has a limited effect on the temperature gradient and solidification rate at the solidification interface due to the convection mode of melt flow is still Marangoni convection.
Originality/value
This work provided a deeper understanding of the interaction mechanism between the magnetic field and melt flow inside the molten pool, and provided practical references for magnetic field-assisted L-DED equipment design.
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K. Li, B.Q. Li, J. Handa and H.C. de Groh
The quality of crystals grown in space can be diversely affected by the melt flows induced by g‐jitter associated with a space vehicle. This paper presents a full…
Abstract
Purpose
The quality of crystals grown in space can be diversely affected by the melt flows induced by g‐jitter associated with a space vehicle. This paper presents a full three‐dimensional (3D) transient finite element analysis of the complex fluid flow and heat and mass transfer phenomena in a simplified Bridgman crystal growth configuration under the influence of g‐jitter perturbations and magnetic fields.
Design/methodology/approach
The model development is based on the Galerkin finite element solution of the magnetohydrodynamic governing equations describing the thermal convection and heat and mass transfer in the melt. A physics‐based re‐numbering algorithm is used to make the formidable 3D simulations computationally feasible. Simulations are made using steady microgravity, synthetic and real g‐jitter data taken during a space flight.
Findings
Numerical results show that g‐jitter drives a complex, 3D, time dependent thermal convection and that velocity spikes in response to real g‐jitter disturbances in space flights, resulting in irregular solute concentration distributions. An applied magnetic field provides an effective means to suppress the deleterious convection effects caused by g‐jitter. Based on the simulations with applied magnetic fields of various strengths and orientations, the magnetic field aligned with the thermal gradient provides an optimal damping effect, and the stronger magnetic field is more effective in suppressing the g‐jitter induced convection. While the convective flows and solute transport are complex and truly 3D, those in the symmetry plane parallel to the direction of g‐jitter are essentially two‐dimensional (2D), which may be approximated well by the widely used 2D models.
Originality/value
The physics‐based re‐numbering algorithm has made possible the large scale finite element computations for 3D g‐jitter flows in a magnetic field. The results indicate that an applied magnetic field can be effective in suppressing the g‐jitter driven flows and thus enhance the quality of crystals grown in space.
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M. Kothandapani and V. Pushparaj
This paper aims to investigate the consequence of the combined impacts of an induced magnetic field and thermal radiation on peristaltic transport of a Carreau nanofluid in a…
Abstract
Purpose
This paper aims to investigate the consequence of the combined impacts of an induced magnetic field and thermal radiation on peristaltic transport of a Carreau nanofluid in a vertical tapered asymmetric channel. The model applied for the nanofluid comprises the effects of Brownian motion and thermophoresis.
Design/methodology/approach
The governing equations have been simplified under the widespread assumption of long-wavelength and low-Reynolds number approximations. The reduced coupled nonlinear equations of momentum and magnetic force function have also been solved analytically using the regular perturbation method.
Findings
The physical features of emerging parameters have been discussed by drawing the graphs of velocity, temperature, nanoparticle concentration profile, magnetic force function, current density, heat transfer coefficient and stream function. It has been realized that the magnetic force function is increased with the increase of Hartmann number, magnetic Reynolds number and mean flow rate.
Originality/value
It may be first paper in which the effect of induced magnetic field on peristaltic flow of non-Newtonian nanofluid in a tapered asymmetric channel has been studied.
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Laura Darabant, Mihaela Cretu, Radu V. Ciupa, Dan D. Micu and Denisa Stet
The purpose of this paper is to estimate the electrical field induced in the spinal cord and nearby area during lumbar magnetic stimulation.
Abstract
Purpose
The purpose of this paper is to estimate the electrical field induced in the spinal cord and nearby area during lumbar magnetic stimulation.
Design/methodology/approach
The spinal cord is modelled as a continuous cylinder, while the vertebral column is also represented by a concentric interrupted cylinder. The coil used for magnetic stimulation is a figure of eight, whose centre is placed above T12‐L1 vertebras. The electrical field is induced and its derivative is computed using the finite difference method.
Findings
Preliminary results suggest that magnetic stimulation may be able to induce a sufficiently intense electric field inside the spinal cord, leading to the direct activation of spinal nerve roots.
Practical implications
If the spinal cord can be stimulated directly by magnetic stimulation, this technique can facilitate functional motor activities, including standing and stepping in paralyzed people, in a non‐invasive way.
Originality/value
The authors revealed the fact that functional magnetic stimulation can be applied to the spinal cord, and should be further investigated as an alternative to invasive techniques such as electrical stimulation.
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Panteleimon A. Bakalis and Pavlos M. Hatzikonstantinou
The steady laminar quasi-3D fully developed magnetohydrodynamic (MHD) flow of a liquid metal in a curved annular channel is studied in order to determine the effect of the magnetic…
Abstract
Purpose
The steady laminar quasi-3D fully developed magnetohydrodynamic (MHD) flow of a liquid metal in a curved annular channel is studied in order to determine the effect of the magnetic field on the velocity distribution. The paper aims to discuss this issue.
Design/methodology/approach
Due to the fluid motion under the effect of the applied transverse external magnetic field, an additional magnetic field and an electric current density are induced. A hybrid formulation is used for the induced electric current density, implementing for its axial component the Ohm’s law and for its transverse components the Ampere’s law. The suggested formulation (denominated h-formulation) is combined with the extended Continuity Vorticity Pressure numerical variational method for MHD flows.
Findings
Results are obtained for different values of curvature ratios and Hartmann numbers. It is proved that as the strength of the magnetic field increases, two side regions of velocity jets are formulated in the right and in the left half sides of the inner cylinder in a direction parallel to the external magnetic field. The magnitude of the axial velocity at each region is determined by the balance of the centrifugal and the electromagnetic forces. The results help to better understand the MHD flow in toroidal ducts.
Originality/value
The results aim to help to a better understanding of the MHD flow in curved ducts.