scholarly journals Thermo-Optical Mechanical Waves in a Rotating Solid Semiconductor Sphere Using the Improved Green–Naghdi III Model

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2902
Author(s):  
Ahmed E. Abouelregal ◽  
Marin Marin ◽  
Sameh S. Askar
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Solid Sphere ◽  
Elastic Displacement ◽  
Mechanical Waves ◽  
Proposed Model ◽  
Rotation Parameters ◽  
Basic Equations ◽  
The Impact ◽  
Delay Factor

The current study investigates thermophotovoltaic interactions using a new mathematical model of thermoelasticity established on a modification of the Green–Naghdi model of type III (GN-III). The basic equations, in which the heat transfer is in the form of the Moore–Gibson–Thompson (MGT) equation, are derived by adding a single delay factor to the GN-III model. The impact of temperature and electrical elastic displacement of semiconductors throughout the excited thermoelectric mechanism can be studied theoretically using this model. The proposed model was used to investigate the interactions between the processes of thermoelastic plasma in a rotating semiconductor solid sphere that was subjected to a thermal shock and crossed to an externally applied magnetic field. The influence of rotation parameters on various photothermal characteristics of silicon solid was presented and explored using the Laplace technique.

scholarly journals Effects of a Rotating Cone on the Mixed Convection in a Double Lid-Driven 3D Porous Trapezoidal Nanofluid Filled Cavity under the Impact of Magnetic Field

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 449 ◽  
Author(s):  
Ali J. Chamkha ◽  
Fatih Selimefendigil ◽  
Hakan F. Oztop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Nusselt Number ◽  
Aspect Ratio ◽  
Mixed Convection ◽  
Average Nusselt Number ◽  
Volume Fraction ◽  
Rotational Velocity ◽  
Rotating Cone ◽  
The Impact

Effects of a rotating cone in 3D mixed convection of CNT-water nanofluid in a double lid-driven porous trapezoidal cavity is numerically studied considering magnetic field effects. The numerical simulations are performed by using the finite element method. Impacts of Richardson number (between 0.05 and 50), angular rotational velocity of the cone (between −300 and 300), Hartmann number (between 0 and 50), Darcy number (between 10 − 4 and 5 × 10 − 2 ), aspect ratio of the cone (between 0.25 and 2.5), horizontal location of the cone (between 0.35 H and 0.65 H) and solid particle volume fraction (between 0 and 0.004) on the convective heat transfer performance was studied. It was observed that the average Nusselt number rises with higher Richardson numbers for stationary cone while the effect is reverse for when the cone is rotating in clockwise direction at the highest supped. Higher discrepancies between the average Nusselt number is obtained for 2D cylinder and 3D cylinder configuration which is 28.5% at the highest rotational speed. Even though there are very slight variations between the average Nu values for 3D cylinder and 3D cone case, there are significant variations in the local variation of the average Nusselt number. Higher enhancements in the average Nusselt number are achieved with CNT particles even though the magnetic field reduced the convection and the value is 84.3% at the highest strength of magnetic field. Increasing the permeability resulted in higher local and average heat transfer rates for the 3D porous cavity. In this study, the aspect ratio of the cone was found to be an excellent tool for heat transfer enhancement while 95% enhancements in the average Nusselt number were obtained. The horizontal location of the cone was found to have slight effects on the Nusselt number variations.

Dufour and Soret effects on Darcy-Forchheimer flow of second-grade fluid with the variable magnetic field and thermal conductivity

2020 ◽  
Vol 30 (9) ◽  
pp. 4331-4347 ◽  
Author(s):  
Ambreen A. Khan ◽  
S. Naeem ◽  
R. Ellahi ◽  
Sadiq M. Sait ◽  
K. Vafai
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Thermal Conductivity ◽  
Variable Magnetic Field ◽  
Second Grade ◽  
Second Grade Fluid ◽  
Content Type ◽  
Grade Fluid ◽  
The Impact ◽  
Forchheimer Flow

Purpose This study aims to investigate the effect of two-dimensional Darcy-Forchheimer flow over second-grade fluid with linear stretching. Heat transfer through convective boundary conditions is taken into account. Design/methodology/approach Nonlinear coupled governing equations are tackled with a homotopy algorithm, while for numerical computation the computer software package BVPh 2.0 is used. The convergence analysis is also presented for the validation of analytical and numerical results. Findings Valuation for the impact of key parameters such as variable thermal conductivity, Dufour and Soret effects and variable magnetic field in an electrically conducted fluid on the velocity, concentration and temperature profiles are graphically illustrated. It is observed from the results that temperature distribution rises by Dufour number whereas concentration distribution rises by Soret number. The Forchheimer number and porosity parameter raise the skin friction coefficient. The permeable medium has a vital impact and can help in reining the rate of heat transfer. Practical implications The permeable medium has a vital impact and can help in reining the rate of heat transfer. Originality/value To the best of the authors’ knowledge, this study is reported for the first time.

scholarly journals Slip Effects on Unsteady Oblique Stagnation Point Flow of Nanofluid in a View of Inclined Magnetic Field

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Rizwana Rizwana ◽  
Azad Hussain ◽  
S. Nadeem
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Stagnation Point ◽  
Flow Behavior ◽  
Casson Fluid ◽  
Stagnation Point Flow ◽  
Working Fluid ◽  
Petroleum Reservoir ◽  
Metallic Nanoparticle ◽  
The Impact

This study may be applicable in heavy power engine and cooling of a nuclear reactor, insulation for buildings, petroleum reservoir operations, and magnetic material processing solar energy collectors. In this manuscript, the slip results are evaluated for the non-Newtonian fluid on the oblique stagnation point flow of induced magnetic field over the oscillating surface. The valuation of heat flux is examined through the Fourier law of heat transfer. The metallic nanoparticle Copper Cu is within the base fluid, and water is utilized in the analysis. Nanofluids have benefits such as steadiness of the working fluid, decreasing blockage, clogs, decreasing prices, decreasing the friction coefficient, and decreasing the size of the heat transfer system. Similarity variables are utilized to convert the developed flow into higher nonlinear coupled ordinary differential equations (ODE) which are tackled numerically using a mathematical technique such as the bvp4c method in Maple and Matlab software. According to the present geometry, the flow behavior of the operating nanofluid has analyzed by stream lines. Disparities in velocity and temperature profile are demonstrated by graphs to describe the effects of controlling parameters. The Casson fluid parameter enhances the velocity of the fluid. The system heats up by the impact of Joule heating and dissipation.

Nonhomogeneous model for conjugate mixed convection of nanofluid and entropy generation in an enclosure in presence of inclined magnetic field with Joule heating

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Subhasree Dutta ◽  
Somnath Bhattacharyya ◽  
Ioan Pop
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Entropy Generation ◽  
Joule Heating ◽  
Conjugate Heat Transfer ◽  
Inclined Magnetic Field ◽  
Content Type ◽  
The Impact ◽  
The Magnetic Field

Purpose This study aims to numerically analyse the impact of an inclined magnetic field and Joule heating on the conjugate heat transfer because of the mixed convection of an Al2O3–water nanofluid in a thick wall enclosure. Design/methodology/approach A horizontal temperature gradient together with the shear-driven Flow creates the mixed convection inside the enclosure. The nonhomogeneous model, in which the nanoparticles have a slip velocity because of thermophoresis and Brownian diffusion, is adopted in the present study. The thermal performance is evaluated by determining the entropy generation, which includes the contribution because of magnetic field. A control volume method over a staggered grid arrangement is adopted to compute the governing equations. Findings The Lorentz force created by the applied magnetic field has an adverse effect on the flow and thermal field, and consequently, the heat transfer and entropy generation attenuate because of the presence of magnetic force. The Joule heating enhances the fluid temperature but attenuates the heat transfer. The impact of the magnetic field diminishes as the angle of inclination of the magnetic field is increased, and it manifests as the volume fraction of nanoparticles is increased. Addition of nanoparticles enhances both the heat transfer and entropy generation compared to the clear fluid with enhancement in entropy generation higher than the rate by which the heat transfer augments. The average Bejan number and mixing-cup temperature are evaluated to analyse the thermodynamic characteristics of the nanofluid. Originality/value This literature survey suggests that the impact of an inclined magnetic field and Joule heating on conjugate heat transfer based on a two-phase model has not been addressed before. The impact of the relative slip velocity of nanoparticles diminishes as the magnetic field becomes stronger.

scholarly journals A Numerical Approach for the Heat Transfer Flow of Carboxymethyl Cellulose-Water Based Casson Nanofluid from a Solid Sphere Generated by Mixed Convection under the Influence of Lorentz Force

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1094 ◽  
Author(s):  
Firas A. Alwawi ◽  
Hamzeh T. Alkasasbeh ◽  
Ahmed M. Rashad ◽  
Ruwaidiah Idris
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Skin Friction ◽  
Carboxymethyl Cellulose ◽  
Solid Sphere ◽  
Numerical Approach ◽  
Casson Nanofluid ◽  
Keller Box Method ◽  
Water Based ◽  
The Impact

The heat transfer of a carboxymethyl cellulose aqueous solution (CMC-water) based Casson nanofluid, flowing under the impact of a variable-strength magnetic field in mixed convection around a solid sphere, has been examined in this work. Aluminum (Al), copper (Cu), and silver (Ag) nanoparticles were employed to support the heat transfer characteristics of the host fluid. A numerical approach called the Keller-box method (KBM) was used to solve the governing system for the present problem, and also to examine and analyze the numerical and graphic results obtained by the MATLAB program, verifying their accuracy through comparing them with the prior literature. The results demonstrate that a Al–CMC-water nanoliquid is superior in terms of heat transfer rate and skin friction. The velocity of CMC-water is higher with Ag compared to Al–CMC-water, and Ag–CMC-water possesses the lowest temperature. Growing mixed parameter values result in a rising skin friction, velocity and Nusselt number or decline in temperature.

Effect of Local Magnetic Fields on Electrically Conducting Fluid Flow and Heat Transfer

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Xidong Zhang ◽  
Hulin Huang
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Reynolds Number ◽  
Vortex Shedding ◽  
Conducting Fluid ◽  
Local Magnetic Field ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Electrically Conducting Fluid ◽  
The Impact

The prediction of electrically conducting fluid past a localized zone of applied magnetic field is the key for many practical applications. In this paper, the characteristics of flow and heat transfer (HI) for a liquid metal in a rectangular duct under a local magnetic field are investigated numerically using a three-dimensional model and the impact of some parameters, such as constrainment factor, κ, interaction parameter, N, and Reynolds number, Re, is also discussed. It is found that, in the range of Reynolds number 100 ≤ Re ≤ 900, the flow structures can be classified into the following four typical categories: no vortices, one pair of magnetic vortices, three pairs of vortices and vortex shedding. The simulation results indicate that the local heterogeneous magnetic field can enhance the wall-heat transfer and the maximum value of the overall increment of HI is about 13.6%. Moreover, the pressure drop penalty (ΔPpenalty) does not increasingly depend on the N for constant κ and Re. Thus, the high overall increment of HI can be obtained when the vortex shedding occurs.

scholarly journals Effect of magnetic field on fluid flow characteristics and augmentation of heat transfer in a heat exchanger

2021 ◽  
Author(s):  
Mohammed Almeshaal ◽  
◽  
Sujoy Saha ◽  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Control Volume ◽  
Flow Characteristics ◽  
Research Area ◽  
Flow Parameters ◽  
Fluid Flow Characteristics ◽  
The Impact

The study of fluid flow, subjected to an external magnetic field has become an attractive and demanding research area because of its huge applications. In this work, water base magnetic nanofluid dynamics, taking into account the Magnetohydrodynamics (MHD) phenomenon has been explicitly investigated. In this study, governing equations are coupled with Magnetohydrodynamics (MHD) and are solved with the help of a finite volume procedure based on a control volume approach. The numerical outcomes of the simulation are depicted and discussed sequentially in terms of different contour and flow parameters. The impact of Magnetic number arising from Magneto Hydro Dynamics (MHD) ranging from 302 to 377 for a fixed Reynolds number of 100 on the flow characteristics has been presented in detail. The flow parameters like wall shear and pressure of wall are increased with increasing Magnetic number and the number of recirculating bubbles increases with decreasing in Magnetic number. Thus, to generate the maximum number of recirculating bubbles,a lower magnetic number is being recommended. The formation of the recirculating zone increases the retention time of fluid which results in the enhancement of heat transfer for a specific surface of a heat exchanger.

Magnetic Field and Thermal Radiation Effects in Peristaltic Flow With Heat and Mass Convection

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
T. Hayat ◽  
Aneela Bibi ◽  
H. Yasmin ◽  
Fuad E. Alsaadi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Thermal Radiation ◽  
Transfer Coefficient ◽  
Radiation Effects ◽  
Schmidt Number ◽  
Oscillatory Behavior ◽  
Jeffrey Fluid ◽  
The Impact

This paper scrutinizes the impact of thermal radiation and applied magnetic field on Jeffrey fluid with peristalsis. The effects of Joule heating and viscous dissipation are retained. Convective conditions are imposed for the heat and mass transfer analysis. Lubrication approach is considered for the analysis. Expressions for pressure gradient, stream function, temperature, concentration, and heat transfer coefficient are developed and physically interpreted through illustrations. It is revealed that temperature enhances for higher estimation of Brinkman and Hartmann numbers, while it decays for larger Biot number. Furthermore, the concentration decreases for varying Schmidt number. Heat transfer coefficient has an oscillatory behavior for larger estimation of radiation parameter.

scholarly journals Numerical analysis of flow and heat transfer in a thin film along an unsteady stretching cylinder

2021 ◽  
Vol 25 (Spec. issue 2) ◽  
pp. 441-448
Author(s):  
Azeem Shahzad ◽  
Bushra Habib ◽  
Muhammad Nadeem ◽  
Muhammad Kamran ◽  
Hijaz Ahma ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Heat Transfer ◽  
Boundary Layer ◽  
External Magnetic Field ◽  
Stretching Cylinder ◽  
Similarity Transformations ◽  
Flow And Heat Transfer ◽  
Governing System ◽  
The Impact

In this framework, the boundary-layer mass and heat flow in a liquid film over an unsteady stretching cylinder are discussed under the influence of a magnetic field. By means of the similarity transformations the highly non-linear governing system of PDE is converted to ODE. We use the built-in function bvp4c in MATLAB to solve this system of ODE. The impact of distinctive parameters on velocity and temperature profile in the existence of an external magnetic field is depicted via graphs and deep analysis is also presented.

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