scholarly journals MHD Natural Convection of a Fe3O4–Water Nanofluid within an Inside Round Diagonal Corner Square Cavity with Existence of Magnetic Source

2020 ◽  
Vol 10 (9) ◽  
pp. 3236 ◽  
Author(s):  
Faouzi Nasri ◽  
Yahya Ali Rothan ◽  
Rached Nciri ◽  
Chaouki Ali
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Transfer Problem ◽  
The Finite Element Method ◽  
Square Cavity ◽  
Nanofluid Flow ◽  
Velocity Magnitude ◽  
Flow And Heat Transfer ◽  
Magnetic Source ◽  
Cold Walls

This study concerns a numerical investigation of a magnetohydrodynamic (MHD) natural convection of a Fe3O4–water nanofluid filled within a round diagonal corner square cavity. The cavity was subjected to imposed temperatures (hot and cold walls) and one magnetic source. The nanofluid flow and heat transfer problem was mathematically modeled and its dimensionless problem was established. The finite element method was implemented in order to solve the MHD problem. The effects of the Rayleigh number, Hartmann number and round corner radius on the nanofluid flow (streamlines and velocity magnitude) and heat transfer (isotherms and temperature distribution) were evaluated. Heat transfer was assessed when the convection or the conduction dominates with regard to the nature of the flow.

scholarly journals Radiative MHD Sutterby Nanofluid Flow Past a Moving Sheet: Scaling Group Analysis

Mathematics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1430
Author(s):  
Mohammed M. Fayyadh ◽  
Kohilavani Naganthran ◽  
Md Faisal Md Basir ◽  
Ishak Hashim ◽  
Rozaini Roslan
Keyword(s):  
Heat Transfer ◽  
Thermal Radiation ◽  
Numerical Solutions ◽  
Transfer Problem ◽  
Group Analysis ◽  
Shrinking Sheet ◽  
Nanofluid Flow ◽  
Stagnation Region ◽  
Flow And Heat Transfer ◽  
Scaling Group

The present theoretical work endeavors to solve the Sutterby nanofluid flow and heat transfer problem over a permeable moving sheet, together with the presence of thermal radiation and magnetohydrodynamics (MHD). The fluid flow and heat transfer features near the stagnation region are considered. A new form of similarity transformations is introduced through scaling group analysis to simplify the governing boundary layer equations, which then eases the computational process in the MATLAB bvp4c function. The variation in the values of the governing parameters yields two different numerical solutions. One of the solutions is stable and physically reliable, while the other solution is unstable and is associated with flow separation. An increased effect of the thermal radiation improves the rate of convective heat transfer past the permeable shrinking sheet.

scholarly journals Hydrothermal and Entropy Investigation of Ag/MgO/H2O Hybrid Nanofluid Natural Convection in a Novel Shape of Porous Cavity

2021 ◽  
Vol 11 (4) ◽  
pp. 1722
Author(s):  
Nidal Abu-Libdeh ◽  
Fares Redouane ◽  
Abderrahmane Aissa ◽  
Fateh Mebarek-Oudina ◽  
Ahmad Almuhtady ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Hybrid Nanofluid ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Nanofluid Flow ◽  
The Magnetic Field

In this study, a new cavity form filled under a constant magnetic field by Ag/MgO/H2O nanofluids and porous media consistent with natural convection and total entropy is examined. The nanofluid flow is considered to be laminar and incompressible, while the advection inertia effect in the porous layer is taken into account by adopting the Darcy–Forchheimer model. The problem is explained in the dimensionless form of the governing equations and solved by the finite element method. The results of the values of Darcy (Da), Hartmann (Ha) and Rayleigh (Ra) numbers, porosity (εp), and the properties of solid volume fraction (ϕ) and flow fields were studied. The findings show that with each improvement in the Ha number, the heat transfer rate becomes more limited, and thus the magnetic field can be used as an outstanding heat transfer controller.

scholarly journals Effect of Magnetic Field on Mixed Convection Heat Transfer in a Lid-Driven Square Cavity

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
N. A. Bakar ◽  
A. Karimipour ◽  
R. Roslan
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Convection Heat Transfer ◽  
Simple Algorithm ◽  
Square Cavity ◽  
Nusselt Numbers ◽  
Flow And Heat Transfer ◽  
Vertical Walls ◽  
Cold Walls ◽  
Volume Method

The effect of magnetic field on fluid flow and heat transfer in two-dimensional square cavity is analyzed numerically. The vertical walls are insulated; the top wall is maintained at cold temperature, Tc while the bottom wall is maintained at hot temperature, Th where Th>Tc. The dimensionless governing equations are solved using finite volume method and SIMPLE algorithm. The streamlines and isotherm plots and the variation of Nusselt numbers on hot and cold walls are presented.

scholarly journals Nanofluid convection taking into account the Soret effect and its impact on heat transfer and fluid flow

2020 ◽  
Vol 330 ◽  
pp. 01021
Author(s):  
Ibtissem Mhamdi ◽  
Fakhreddine S. Oueslati ◽  
Rachid Bennacer
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluid Flow ◽  
Soret Effect ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Nanoparticle Concentration ◽  
Governing Equations ◽  
Square Cavity ◽  
Flow And Heat Transfer

The present study is a numerical simulation of natural convection in nanofluids, within in a square cavity differentially heated, to identify the fluid flow and heat transfer by considering the Soret effect during which a temperature gradient in a binary mixture gives rise to a concentration gradient. The governing equations solved numerically using the finite element method following the use of COMSOL Multiphysics. The effects of various parameters, the Rayleigh number, the nanoparticle concentration and the type of nanofluid are analyzed. Our simulations reveal that the heterogeneity of the nanofluid, which is generated by the Soret effect, increases the heat transfer.

Fundamental Issues and Recent Advancements in Analysis of Aircraft Brake Natural Convective Cooling

1998 ◽  
Vol 120 (4) ◽  
pp. 840-857 ◽  
Author(s):  
M. P. Dyko ◽  
K. Vafai
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flow Field ◽  
Three Dimensional ◽  
Convective Cooling ◽  
Cooling Flow ◽  
Physical Mechanisms ◽  
Braking System ◽  
Flow And Heat Transfer ◽  
Convection Cooling

A heightened awareness of the importance of natural convective cooling as a driving factor in design and thermal management of aircraft braking systems has emerged in recent years. As a result, increased attention is being devoted to understanding the buoyancy-driven flow and heat transfer occurring within the complex air passageways formed by the wheel and brake components, including the interaction of the internal and external flow fields. Through application of contemporary computational methods in conjunction with thorough experimentation, robust numerical simulations of these three-dimensional processes have been developed and validated. This has provided insight into the fundamental physical mechanisms underlying the flow and yielded the tools necessary for efficient optimization of the cooling process to improve overall thermal performance. In the present work, a brief overview of aircraft brake thermal considerations and formulation of the convection cooling problem are provided. This is followed by a review of studies of natural convection within closed and open-ended annuli and the closely related investigation of inboard and outboard subdomains of the braking system. Relevant studies of natural convection in open rectangular cavities are also discussed. Both experimental and numerical results obtained to date are addressed, with emphasis given to the characteristics of the flow field and the effects of changes in geometric parameters on flow and heat transfer. Findings of a concurrent numerical and experimental investigation of natural convection within the wheel and brake assembly are presented. These results provide, for the first time, a description of the three-dimensional aircraft braking system cooling flow field.

scholarly journals Computational Performance of Disparate Lattice Boltzmann Scenarios under Unsteady Thermal Convection Flow and Heat Transfer Simulation

Computation ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 65
Author(s):  
Aditya Dewanto Hartono ◽  
Kyuro Sasaki ◽  
Yuichi Sugai ◽  
Ronald Nguele
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Natural Convection ◽  
Lattice Boltzmann ◽  
Numerical Results ◽  
Convection And Heat Transfer ◽  
Steady State Condition ◽  
Physical Systems ◽  
Flow And Heat Transfer ◽  
Computational Performance

The present work highlights the capacity of disparate lattice Boltzmann strategies in simulating natural convection and heat transfer phenomena during the unsteady period of the flow. Within the framework of Bhatnagar-Gross-Krook collision operator, diverse lattice Boltzmann schemes emerged from two different embodiments of discrete Boltzmann expression and three distinct forcing models. Subsequently, computational performance of disparate lattice Boltzmann strategies was tested upon two different thermo-hydrodynamics configurations, namely the natural convection in a differentially-heated cavity and the Rayleigh-Bènard convection. For the purposes of exhibition and validation, the steady-state conditions of both physical systems were compared with the established numerical results from the classical computational techniques. Excellent agreements were observed for both thermo-hydrodynamics cases. Numerical results of both physical systems demonstrate the existence of considerable discrepancy in the computational characteristics of different lattice Boltzmann strategies during the unsteady period of the simulation. The corresponding disparity diminished gradually as the simulation proceeded towards a steady-state condition, where the computational profiles became almost equivalent. Variation in the discrete lattice Boltzmann expressions was identified as the primary factor that engenders the prevailed heterogeneity in the computational behaviour. Meanwhile, the contribution of distinct forcing models to the emergence of such diversity was found to be inconsequential. The findings of the present study contribute to the ventures to alleviate contemporary issues regarding proper selection of lattice Boltzmann schemes in modelling fluid flow and heat transfer phenomena.

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