scholarly journals Optimal inductor design for nanofluid heating characterisation

2015 ◽  
Vol 32 (7) ◽  
pp. 1870-1892 ◽  
Author(s):  
Roberta Bertani ◽  
Flavio Ceretta ◽  
Paolo Di Barba ◽  
Fabrizio Dughiero ◽  
Michele Forzan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Real Life ◽  
Evolutionary Computing ◽  
Petri Dish ◽  
Element Analysis ◽  
Content Type ◽  
Magnetic Fluid Hyperthermia ◽  
Set Up ◽  
Laboratory Prototype

Purpose – Magnetic fluid hyperthermia experiment requires a uniform magnetic field in order to control the heating rate of a magnetic nanoparticle fluid for laboratory tests. The automated optimal design of a real-life device able to generate a uniform magnetic field suitable to heat cells in a Petri dish is presented. The paper aims to discuss these issues. Design/methodology/approach – The inductor for tests has been designed using finite element analysis and evolutionary computing coupled to design of experiments technique in order to take into account sensitivity of solutions. Findings – The geometry of the inductor has been designed and a laboratory prototype has been built. Results of preliminary tests, using a previously synthesized and characterized magneto fluid, are presented. Originality/value – Design of experiment approach combined with evolutionary computing has been used to compute the solution sensitivity and approximate a 3D Pareto front. The designed inductor has been tested in an experimental set-up.

MHD natural convection of Cu/H2O nanofluid in a horizontal semi-cylinder with a local triangular heater

2018 ◽  
Vol 28 (12) ◽  
pp. 2979-2996 ◽  
Author(s):  
A.S. Dogonchi ◽  
Mikhail A. Sheremet ◽  
Ioan Pop ◽  
D.D. Ganji
Keyword(s):  
Magnetic Field ◽  
Rayleigh Number ◽  
Free Convection ◽  
Shape Factor ◽  
Uniform Magnetic Field ◽  
Hartmann Number ◽  
Volume Fraction ◽  
Horizontal Cylinder ◽  
Content Type ◽  
Nanoparticles Volume Fraction

Purpose The purpose of this study is to investigate free convection of copper-water nanofluid in an upper half of circular horizontal cylinder with a local triangular heater under the effects of uniform magnetic field and cold cylinder shell using control volume finite element method (CVFEM). Design/methodology/approach Governing equations formulated in dimensionless stream function, vorticity and temperature variables using the single-phase nanofluid model with Brinkman correlation for the effective dynamic viscosity and Hamilton and Crosser model for the effective thermal conductivity have been solved numerically by CVFEM. Findings The impacts of control parameters such as the Rayleigh number, Hartmann number, nanoparticles volume fraction, local triangular heater size, shape factor on streamlines and isotherms as well as local and average Nusselt numbers have been examined. The outcomes indicate that the average Nusselt number is an increasing function of the Rayleigh number, shape factor and nanoparticles volume fraction, while it is a decreasing function of the Hartmann number. Originality/value A complete study of the free convection of copper-water nanofluid in an upper half of circular horizontal cylinder with a local triangular heater under the effects of uniform magnetic field and cold cylinder shell using CVFEM is addressed.

Analytical sub-domain model for predicting open-circuit field of permanent magnet vernier machine accounting for tooth tips

2016 ◽  
Vol 35 (2) ◽  
pp. 624-640 ◽  
Author(s):  
Y. Oner ◽  
Z.Q. Zhu ◽  
L.J. Wu ◽  
X. Ge
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Open Circuit ◽  
Air Gap ◽  
Domain Model ◽  
Direct Drive ◽  
Element Analysis ◽  
Cogging Torque ◽  
Content Type ◽  
Flux Modulation

Purpose – Due to high electromagnetic torque at low speed, vernier machines are suitable for direct-drive applications such as electric vehicles and wind power generators. The purpose of this paper is to present an exact sub-domain model for analytically predicting the open-circuit magnetic field of permanent magnet vernier machine (PMVM) including tooth tips. The entire field domain is divided into five regions, viz. magnets, air gap, slot openings, slots, and flux-modulation pole slots (FMPs). The model accounts for the influence of interaction between PMs, FMPs and slots, and radial/parallel magnetization. Design/methodology/approach – Magnetic field distributions for slot and air-gap, flux linkage, back-EMF and cogging torque waveforms are obtained from the analytical method and validated by finite element analysis (FEA). Findings – It is found that the developed sub-domain model including tooth tips is very accurate and is applicable to PMVM having any combination of slots/FMPs/PMs. Originality/value – The main contributions include: accurate sub-domain model for PMVM is proposed for open-circuit including tooth-tip which cannot be accounted for in literature; the model accounts the interaction between flux modulation pole (FMP) and slot; developed sub-domain model is accurate and applicable to any slot/FMP/PM combinations; and it has investigated the influence of FMP/slot opening width/height on cogging torque.

Empirical investigation of wireless sensor network performance in noisy environments

2014 ◽  
Vol 12 (1) ◽  
pp. 29-38
Author(s):  
Silvanus Teneng Kiyang ◽  
Robert Van Zyl
Keyword(s):  
Ambient Noise ◽  
Network Performance ◽  
Signal To Noise Ratio ◽  
Real Life ◽  
Wireless Sensor ◽  
Mathematical Tool ◽  
Content Type ◽  
The Real ◽  
Test Platform ◽  
Set Up

Purpose – The purpose of this work is to assess the influence of ambient noise on the performance of wireless sensor networks (WSNs) empirically and, based on these findings, develop a mathematical tool to assist technicians to determine the maximum inter-node separation before deploying a new WSN. Design/methodology/approach – A WSN test platform is set up in an electromagnetically shielded environment (RF chamber) to accurately control and quantify the ambient noise level. The test platform is subsequently placed in an operational laboratory to record network performance in typical unshielded spaces. Results from the RF chamber and the real-life environments are analysed. Findings – A minimum signal-to-noise ratio (SNR) at which the network still functions was found to be of the order 30 dB. In the real-life scenarios (machines, telecommunications and computer laboratories), the measured SNR exceeded this minimum value by more than 20 dB. This is due to the low ambient industrial noise levels observed in the 2.4 GHz ISM band for typical environments found at academic institutions. It, therefore, suggests that WSNs are less prone to industrial interferences than anticipated. Originality/value – A predictive mathematical tool is developed that can be used by technicians to determine the maximum inter-node separation before the WSN is deployed. The tool yields reliable results and promises to save installation time.

A study for steady nanofluid flow between parallel plates

2017 ◽  
Vol 34 (8) ◽  
pp. 2514-2527 ◽  
Author(s):  
Syed Tauseef Mohyud-din ◽  
Muhammad Asad Iqbal ◽  
Muhammad Shakeel
Keyword(s):  
Magnetic Field ◽  
Differential Equations ◽  
Uniform Magnetic Field ◽  
Design Methodology ◽  
Magnetic Parameter ◽  
Parallel Plates ◽  
Nanofluid Flow ◽  
Content Type ◽  
Viscosity Parameter ◽  
Variation Of Parameters

Purpose In this paper, the authors study the behavior of heat and mass transfer between parallel plates of a steady nanofluid flow in the presence of a uniform magnetic field. In the model of nanofluids, the essential effect of thermophoresis and Brownian motion has been encompassed. Design/methodology/approach The variation of parameters method has been exploited to solve the differential equations of nanofluid model. The legitimacy of the variation of parameters method has been corroborated by a comparison of foregoing works by many authors on viscous fluid. Findings An analysis of the model is performed for different parameters, namely, viscosity parameter, Brownian parameter, thermophoretic parameter and magnetic parameter. Originality/value The variation of parameters method proves to be very effective in solving nonlinear system of ordinary differential equations which frequently arise in fluid mechanics.

Using uniform magnetic field to obtain the constant output power and transfer efficiency for MCR-WPT

Circuit World ◽  
2019 ◽  
Vol 46 (1) ◽  
pp. 42-47
Author(s):  
Suqi Liu ◽  
Jianping Tan
Keyword(s):  
Magnetic Field ◽  
Output Power ◽  
Uniform Magnetic Field ◽  
Open Space ◽  
Frequency Mode ◽  
Transfer Efficiency ◽  
Fixed Frequency ◽  
Constant Frequency ◽  
Content Type ◽  
Constant Output

Purpose This paper aims to find an approach that achieves constant output power and transfer efficiency in an open space, such as charging pads. Design/methodology/approach In this study, a topology of the five-coil system including two transmitting coils is presented. Also, in a fixed-frequency mode and an open space, this study focuses on the two transmitting coils to achieve the uniform magnetic field and ultimately, attain the constant output power and transfer efficiency. Findings In a fixed-frequency mode and an open space, the constant output power and transfer efficiency is then achieved in experiments by inserting the relay loop into the uniform magnetic field. Practical implications An approach that achieves constant output power and transfer efficiency in an open space. The topology of the five-coil magnetically coupled resonant-wireless power transfer (MCR-WPT) system shows prospective value for various applications, which could be used at designing of wireless battery charger dedicated for cars or mobile phones. Originality/value By comparing the simulation and experimental results, the topology can be optimized in the transmission performance by itself. By doing so, the constant output power and transfer ef?ciency are achieved in the constant frequency mode.

Calculation of Lorentz force in planar EMAT for thickness measurement of steel plate

2017 ◽  
Vol 36 (4) ◽  
pp. 1257-1269 ◽  
Author(s):  
Jun Tu ◽  
Tao Chen ◽  
Zhi Xiong ◽  
Xiaochun Song ◽  
Songling Huang
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Steel Plate ◽  
Physical Phenomenon ◽  
Element Model ◽  
Thickness Measurement ◽  
Three Dimension ◽  
Electromagnetic Acoustic Transducer ◽  
Content Type ◽  
Set Up

Purpose The aim of this paper is to better understand the generation and transmission mechanism of the electromagnetic acoustic transducer (EMAT). Design/methodology/approach A semi-analytical method was used to calculate the Lorentz force. Both the hypothetical magnetic field mirror method and the diffusion equation were adopted to solve the eddy current distribution by variables separation method in time domain. A three-dimension magnetostatic finite element model was used to calculate the static magnetic field and the relative permeability. And an experimental platform with a piezoelectric probe to generate and an EMAT to receive, the ultrasonic wave was set up to verify the distribution of the Lorentz force. Findings The Lorentz force at different time and in different positions of the steel plate can be easily calculated. The experimental results show a good agreement with the analytical results. Originality/value The accurate prediction of the Lorentz force provides an insight into the physical phenomenon of EMAT and a powerful tool to design optimum EMAT.

Self-adaptive migration NSGA and optimal design of inductors for magneto-fluid hyperthermia

2018 ◽  
Vol 35 (4) ◽  
pp. 1727-1746 ◽  
Author(s):  
Elisabetta Sieni ◽  
Paolo Di Barba ◽  
Fabrizio Dughiero ◽  
Michele Forzan
Keyword(s):  
Genetic Algorithms ◽  
Pareto Front ◽  
Real Life ◽  
Computational Effort ◽  
Nsga Ii ◽  
Element Analysis ◽  
Content Type ◽  
Power Inductors ◽  
The Magnetic Field

Purpose The purpose of this paper is to present a modified version of the non-dominated sorted genetic algorithm with an application in the design optimization of a power inductor for magneto-fluid hyperthermia (MFH). Design/methodology/approach The proposed evolutionary algorithm is a modified version of migration-non-dominated sorting genetic algorithms (M-NSGA) that now includes the self-adaption of migration events- non-dominated sorting genetic algorithms (SA-M-NSGA). Moreover, a criterion based on the evolution of the approximated Pareto front has been activated for the automatic stop of the computation. Numerical experiments have been based on both an analytical benchmark and a real-life case study; the latter, which deals with the design of a class of power inductors for tests of MFH, is characterized by finite element analysis of the magnetic field. Findings The SA-M-NSGA substantially varies the genetic heritage of the population during the optimization process and allows for a faster convergence. Originality/value The proposed SA-M-NSGA is able to find a wider Pareto front with a computational effort comparable to a standard NSGA-II implementation.

Market entry of a western company in the Middle East

2011 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Rupert A. Brandmeier ◽  
Sebastian Hain ◽  
Florian Rupp
Keyword(s):  
Middle East ◽  
Market Entry ◽  
Service Sector ◽  
Joint Venture ◽  
Life Experience ◽  
Real Life ◽  
Subject Area ◽  
Content Type ◽  
Intercultural Management ◽  
Set Up

Subject area Entry of a service sector company based in Europe into the Middle East market with focus on Saudi Arabia. Study level/applicability The students should have some familiarity with case studies and should be able to successfully solve easy cases. This case can be used in all courses of general economics and management. It is best suited for courses on market entries, risk management in international business, intercultural management or developing and emerging markets. Case overview Two market entry options are discussed: joint venture set-up with partner and independent direct investment without local partner. A tangible real life experience of the Middle East market will enhance the theoretical presentation and help students to gain practical solutions. Expected learning outcomes The students should be aware of risks and opportunities in the Middle East and Saudi Arabian markets for western companies from the service sector. He/She should be able to prioritize relevant economic data and simultaneously discuss several different options by dealing with complex situations. Supplementary materials Teaching note.

MHD natural convection in a square porous cavity filled with a water-based magnetic fluid in the presence of geothermal viscosity

2018 ◽  
Vol 28 (9) ◽  
pp. 2111-2131 ◽  
Author(s):  
Mikhail A. Sheremet ◽  
Marina S. Astanina ◽  
Ioan Pop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Magnetic Fluid ◽  
Convective Flow ◽  
Uniform Magnetic Field ◽  
Vertical Wall ◽  
Content Type ◽  
Porous Cavity ◽  
Water Based

Purpose The purpose of this paper is a numerical analysis of natural convection in a square porous cavity filled with a water-based magnetic fluid of geothermal viscosity under the effect of inclined uniform magnetic field. Design/methodology/approach The domain of interest includes the square porous cavity filled with a water-based magnetic fluid (W40). Horizontal walls are supposed to be adiabatic, while right vertical wall is kept at constant low temperature and left vertical wall is kept at constant high temperature. An inclined uniform magnetic field affects the fluid flow and heat transfer inside the cavity. The viscosity of the working fluid is proportional to the linearly decreasing function of depth (vertical coordinate) and inversely proportional to the linear function of temperature. It is assumed in the analysis that the flow is laminar. The fluid is Newtonian and the Boussinesq approximation is valid. The governing equations have been discretized using the finite difference method with the uniform grid. Simulations have been carried out for different values of the Rayleigh number, Hartmann number, Darcy number, magnetic field inclination angle and viscosity variation parameters. Findings It has been revealed that an increase in the viscosity parameters leads to the heat transfer enhancement and convective flow intensification. At the same time, this intensification is more essential for high values of the Rayleigh number. Originality/value The originality of this work is to analyze MHD natural convection in a square porous cavity filled with a water-based magnetic fluid of geothermal viscosity. The results would benefit scientists and engineers to become familiar with the analysis of convective heat and mass transfer in nanofluids, and the way to predict the properties of nanofluid convective flow in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors and electronics.

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