scholarly journals Impact of Magnetic Field on the Dynamic Performance of Photovoltaic-Thermal Panel with Nanofluids

2021 ◽  
pp. 35-58
Author(s):  
S. Sami
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Material Properties ◽  
Flow Model ◽  
Dynamic Performance ◽  
Photovoltaic Cell ◽  
Dynamic Mass ◽  
The Subject ◽  
Energy Equations ◽  
Dynamic Heat Transfer

The performance of a hybrid solar collector photovoltaic-thermal solar panel system under a magnetic field using nanofluids was presented hereby. A two-dimensional dynamic heat transfer and fluid flow model was developed to describe the behavior of the photovoltaic cell-thermal panel at different conditions such as solar irradiance, nanoparticles, different magnetic field gauss forces. different material properties, and boundary conditions. The model has been established after the dynamic mass and energy equations coupled with the heat transfer relationships, and thermodynamic properties as well as material properties under different magnetic gauss forces. Comparisons were made against literature data for validation purposes of the predictive model. The model fairly predicted the key parameters under different nanofluids conditions, magnetic fields, and compared well with existing data on the subject.

scholarly journals Impact of the Magnetic Field on the Performance of Heat Pipes Driven by a Photovoltaic–Thermal Panel with Nanofluids

2021 ◽  
Vol 4 (3) ◽  
pp. 60
Author(s):  
Samuel Sami
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Flow Model ◽  
Photovoltaic Cells ◽  
Heat Pipes ◽  
The Subject ◽  
Dynamic Heat Transfer ◽  
Dynamic Conservation ◽  
The Magnetic Field ◽  
Existing Data

A two-dimensional dynamic heat transfer and fluid flow model was developed to describe the behavior of photovoltaic cells and the performance of a hybrid solar collector photovoltaic–thermal solar panel system. The system was assessed under different magnetic field Gauss forces. Nanofluids were used to drive the heat pipes in a thermal panel under different conditions, such as levels of solar irradiance and different boundary conditions. The model was developed based on the equations of the dynamic conservation of mass and energy, coupled with the heat transfer relationships and thermodynamic properties, in addition to the material properties under different magnetic Gauss forces. Comparisons were made with the literature data to validate the predictive model. The model reliably predicted the key parameters under different nanofluid conditions and magnetic fields, and compared well with the existing data on the subject.

Hiemenz magnetic flow of a non-Newtonian fluid of second grade with heat transfer

2000 ◽  
Vol 78 (9) ◽  
pp. 875-882 ◽  
Author(s):  
H A Attia
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Newtonian Fluid ◽  
Second Grade ◽  
Magnetic Flow ◽  
Electrically Conducting ◽  
Flow And Heat Transfer ◽  
Energy Equations ◽  
The Magnetic Field ◽  
Steady Laminar

The steady laminar flow of an incompressible viscous electrically conducting non-Newtonian fluid of second grade impinging normal to a plane wall with heat transfer is investigated. An externally applied uniform magnetic field is applied normal to the wall, which is maintained at a constant temperature. A numerical solution for the governing momentum and energy equations is obtained. The effect of the characteristics of the non-Newtonian fluid and the magnetic field on both the flow and heat transfer is outlined. PACS Nos.: 47.50 and 47.15

Non-isothermal flow of Maxwell fluids above fixed flat plates under the influence of a transverse magnetic field

2011 ◽  
Vol 225 (4) ◽  
pp. 909-916 ◽  
Author(s):  
M M Heyhat ◽  
N Khabazi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Boundary Layer ◽  
Fluid Velocity ◽  
Maxwell Fluid ◽  
Transverse Magnetic ◽  
Deborah Number ◽  
Flat Plates ◽  
Two Dimensional Flow ◽  
Energy Equations

In this article, the magnetohydrodynamic flow and heat transfer of an upper-convected Maxwell fluid is studied theoretically above a flat rigid surface with constant temperature. It is assumed that the Reynolds number of the flow is high enough for boundary layer approximation to be valid. Assuming a laminar, two-dimensional flow above the plate, the concept of stream function coupled with the concept of similarity solution is utilized to reduce the governing equations, which are continuity, momentum, and energy equations, into two ordinary differential equations. The spectral method is used for solving the equations numerically. The effects of magnetic field, and Deborah, Prandtl, and Eckert numbers on the fluid velocity field and heat transfer behaviour are shown in several plots. Obtained results show that fluid velocity can be decreased by increasing the magnetic number while it increases by increasing the Deborah number. Moreover, the thickness of the thermal boundary layer is decreased by increasing the Deborah and Prandtl numbers. It is increased by an increase in the Eckert number.

Magnetic field effect on the buoyancy-driven convection & fluid motion in Fe3O4/water nanofluid filled enclosure with mutual orthogonal heaters

2020 ◽  
pp. 1-27
Author(s):  
Deepak Kumar ◽  
Aditya Kumar ◽  
Sudhakar Subudhi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Volume Fraction ◽  
Fluid Motion ◽  
Magnetic Field Effect ◽  
Step Method ◽  
Square Enclosure ◽  
Classical Correlations ◽  
Buoyancy Driven Convection ◽  
Energy Equations

Abstract The present paper investigates the buoyancy induced flow and heat transfer in a square enclosure filled with Fe3O4/water magnetic nanofluid heated by mutually orthogonal heaters and symmetrically cooled by sidewalls under the influence of strong uniform magnetic field. The nanofluid is experimentally synthesized by two step method and the different thermophysical properties are measured. These experimentally determined properties are compared with the classical correlations available in the literature. Those correlations are found to under-predict dynamic viscosity and thermal conductivity of the nanofluid. The error related with the use of the classical correlations is determined and it increases with the volume fraction. Hence, the experimentally determined properties are directly used in the numerical simulation. The governing equations in form of non-dimensional stream function, vorticity and energy equations containing experimentally determined properties are solved using finite difference method. The consequence of different factors like positions of the heaters, varying range of Rayleigh number (103 ≤ Ra ≤ 106), the extremely low volume fraction of magnetic nanofluids (0 ≤ φ ≤ 0.0007) and Hartmann number (0 ≤ Ha ≤ 75) on the heat transport is studied and reported. The study explains and analyzes the streamlines and isotherms at different conditions. The results show that the positions of horizontal and vertical heater have significant effect on heat transfer and fluid flow inside the enclosure. Furthermore, the increase in Ha enervates the strength of flow and it leads in the deterioration of heat transfer.

Unsteady MHD Flow and Heat Transfer of Dusty Fluid Between Two Cylinders With Variable Physical Properties

2004 ◽  
Author(s):  
Nagarajan Balasubramanian ◽  
Yitung Chen
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Electrical Conductivity ◽  
Outer Cylinder ◽  
Mhd Flow ◽  
Dust Particles ◽  
Dusty Fluid ◽  
Linear Partial Differential Equations ◽  
Different Temperatures ◽  
Energy Equations

A mathematical model for unsteady heat transfer and flow of an electrically conducting, viscous, incompressible dusty fluid in a channel formed between two concentric cylinders is developed. In the model, the fluid is driven along the channel by a constant pressure gradient, and an external magnetic field is applied in the direction perpendicular to the channel flow. The two cylinders are considered electrically insulated, and the surfaces maintained at constant but different temperatures with the outer cylinder being at a higher temperature. The viscosity and electrical conductivity of the fluid are considered varying with temperature. The equations governing flow and temperature distribution of both the fluid and the dust particles are a set of coupled momentum and energy equations. The derived system of non-linear partial differential equations is solved numerically on a two-dimensional computation grid using the Galerkin finite element method. The paper ends with discussions of the effect of the applied magnetic field and the variations in viscosity and electrical conductivity with temperature on the time development of the velocity and temperature distributions for both the fluid and dust particles.

scholarly journals Conjugate Effects of Buoyancy and Magnetic Field on Heat and Fluid Flow Pattern at Low-to-Moderate Prandtl Numbers

2016 ◽  
Vol 66 ◽  
pp. 79-95
Author(s):  
Ridha Djebali ◽  
Mohamed Ammar Abbassi ◽  
Ahlem Rouahi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Rayleigh Number ◽  
Prandtl Number ◽  
Threshold Value ◽  
Electrically Conducting ◽  
Viscous Forces ◽  
Side Walls ◽  
Prandtl Numbers ◽  
Energy Equations

This study aims to present a numerical investigation of unsteady two-dimensional natural convection of an electrically conducting fluid in a square medium under externally imposed magnetic field. A temperature gradient is applied between the two opposing side walls parallel to y-direction, while the floor and ceiling parallel to x-direction are kept adiabatic. The coupled momentum and energy equations associated with the Lorentz ‘decelerating’ force as well as the buoyancy force terms are solved using the single relaxation lattice Boltzmann (LB) approach. The flow is characterized by the Rayleigh number Ra (103-106), the Prandtl number Pr (0.01-10), the Hartman number Ha (0-100) determined by the strength of the imposed magnetic field and its tilt angle from x-axis ranging from 0° to 90°. The changes in the buoyant flow patterns and temperature contours due to the effects of varying the controlling parameters and associated heat transfer are examined. It was found that the developed thermal LB model gives excellent results by comparison with former experimental and numerical findings. Starting from the values 105 of the Rayleigh number Ra and Ha=0, the flow is unsteady multicellular for low Prandtl number typical of liquid metal. Increasing gradually Pr, the flow undergoes transition to steady bicellular. The transition occurs at a threshold value between Pr=0.01 and 0.1. Increasing more the Prandtl number, the flow structure is distorted due to the viscous forces which outweigh the buoyancy forces and a thermal stratification is clearly established. For high Hartman number, the damping effects suppress the unsteady behaviour and results in steady state with extended unicellular pattern in the direction of Lorentz force and the heat transfer rate is reduced considerably.

Homann magnetic flow and heat transfer with uniform suction or injection

2003 ◽  
Vol 81 (10) ◽  
pp. 1223-1230 ◽  
Author(s):  
H A Attia
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Numerical Solutions ◽  
Axisymmetric Flow ◽  
Electrically Conducting ◽  
Uniform Suction ◽  
Flow And Heat Transfer ◽  
Suction Or Injection ◽  
Energy Equations ◽  
The Magnetic Field

The steady axisymmetric flow of an incompressible viscous electrically conducting fluid impinging on a permeable flat plate with heat transfer is investigated. An external uniform magnetic field as well as a uniform suction or injection are applied normal to the plate, which is maintained at a constant temperature. Numerical solutions for the governing momentum and energy equations are obtained. The effect of the magnetic field and the uniform suction or injection on both the flow and heat transfer is presented and discussed.PACS Nos.: 47.50, 47.15

Materials for Electron Beam Information Storage

1969 ◽  
Vol 27 ◽  
pp. 152-153 ◽  
Author(s):  
D. E. Speliotis
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Recent Literature ◽  
Electron Beams ◽  
Information Storage ◽  
The Subject ◽  
The Magnetic Field

The interaction of electron beams with a large variety of materials for information storage has been the subject of numerous proposals and studies in the recent literature. The materials range from photographic to thermoplastic and magnetic, and the interactions with the electron beam for writing and reading the information utilize the energy, or the current, or even the magnetic field associated with the electron beam.

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