scholarly journals Three-dimensional numerical study of mixed convection within a ventilated cavity (Shape ‘ L ‘) crossed by a nanofluid under the effect of a magnetic field

2020 ◽  
Vol 307 ◽  
pp. 01027
Author(s):  
S. KHERROUBI ◽  
K. RAGUI ◽  
N. LABSI ◽  
Y.K. BENKAHLA ◽  
A. BOUTRA
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Numerical Study ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Left Wall ◽  
Ventilated Cavity ◽  
The Right

The present work is dedicated to the three-dimensional numerical study of mixed convection heat transfer, taking place within a ventilated cavity (of shape L) crossed by Cu-water nanofluid. The enclosure is subjected to the action of a magnetic field. The ventilation is assured by two openings of the same size. The cold flow enters by an opening practiced at the top of the left wall, and exits by another opening practiced at the bottom of the right vertical wall. All the cavity walls are maintained at the same temperature, superior to that of the entering flow, except the side walls which are considered as adiabatic. The control parameters are: the Reynolds number and the Hartmann number as well as the nanoparticles volume fraction.

scholarly journals Numerical Simulation of the Natural Convection with Presence of the Nanofluids in Cubical Cavity

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Mohamed Sannad ◽  
Abourida Btissam ◽  
Belarche Lahoucine
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Rayleigh Number ◽  
Volume Fraction ◽  
Numerical Study ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Flow And Heat Transfer ◽  
Heating Section ◽  
The Right

This article consists of a numerical study of natural convection heat transfer in three-dimensional cavity filled with nanofluids. This configuration is heated by a partition maintained at a hot constant and uniform temperature TH. The right and left vertical walls are kept at a cold temperature TC while the rest is adiabatic. The fluid flow and heat transfer in the cavity are studied for different sets of the governing parameters, namely, the nanofluid type, the Rayleigh number Ra = 103, 104, 105, and 106, and the volume fraction Ф varying between Ф = 0 and 0.1. The obtained results show a positive effect of the volume fraction and the Rayleigh number on the heat transfer improvement. The analysis of the results related to the heat transfer shows that the copper-based nanofluid guarantees the best thermal transfer. In addition, the increase of the heating section size and Ra leads to an increased amount of heat. Similarly, increasing the volume fraction improves the intensification of the flow and increases the heat exchange.

Numerical Study of Magnetic Field Effects on Buoyancy Driven Convection in a Non-Isothermally Heated Square Enclosure

2011 ◽  
Vol 312-315 ◽  
pp. 536-541
Author(s):  
Ghanbar Ali Sheikhzadeh ◽  
Mohsen Pirmohammadi ◽  
A. Fattahi ◽  
M.A. Mehrabian
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Hartmann Number ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Magnetic Field Effects ◽  
Left Wall ◽  
Square Enclosure ◽  
The Right ◽  
Sinusoidal Function

Numerical simulation of natural convection heat transfer in the presence of a magnetic field is analyzed in a non-isothermally heated square enclosure. The left wall is heated and cooled with a sinusoidal heat source and the right wall is cooled isothermally. The horizontal walls of the enclosure are adiabatic. The effects of Rayleigh number (Ra = 104, 105 and 106), Hartmann number (Ha = 0, 25, 50 and 100) and amplitude of sinusoidal function (n = 0.25, 0.5 and 1) on temperature and flow fields are analyzed. It is observed that the rate of heat transfer is decreased with increasing the Hartmann number; it is also decreased when decreasing the amplitude of sinusoidal function.

scholarly journals Heat and mass source effect on MHD double-diffusive mixed convection and entropy generation in a curved enclosure filled with nanofluid

2022 ◽  
Vol 27 ◽  
pp. 1-23
Author(s):  
Rujda Parveen ◽  
Tapas Ray Mahapatra
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Richardson Number ◽  
Hartmann Number ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Vertical Wall ◽  
Mass Source ◽  
Left Wall ◽  
The Right

This paper examines the two-dimensional laminar steady magnetohydrodynamic doublediffusive mixed convection in a curved enclosure filled with different types of nanofluids. The enclosure is differentially heated and concentrated, and the heat and mass source are embedded in a part of the left wall having temperature Th (>Tc) and concentration ch (>cc). The right vertical wall is allowed to move with constant velocity in a vertically upward direction to cause a shear-driven flow. The governing equations along with the boundary conditions are transformed into a nondimensional form and are written in stream function-velocity formulation, which is then solved numerically using the Bi-CGStab method. Based on the numerical results, the effects of the dominant parameters such as Richardson number (1 ≤ Ri ≤ 50), Hartmann number (0 ≤ Ha ≤ 60), solid volume fraction of nanoparticles (0.0 ≤ ϕ ≤ 0.02), location and length of the heat and mass source are examined. Results indicate that the augmentation of Richardson number, heat and mass source length and location cause heat and mass transfer to increase, while it decreases when Hartmann number and volume fraction of the nanoparticles increase. The total entropy generation rises by 1.32 times with the growing Richardson number, decreases by 1.21 times and 1.02 times with the rise in Hartmann number and nanoparticles volume fraction, respectively.

scholarly journals Natural Convection and Entropy Generation of MgO/Water Nanofluids in the Enclosure under a Magnetic Field and Radiation Effects

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1277
Author(s):  
Yacine Khetib ◽  
Ahmad Aziz Alahmadi ◽  
Ali Alzaed ◽  
Ahamd Tahmasebi ◽  
Mohsen Sharifpur ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Entropy Generation ◽  
Radiation Effects ◽  
Volume Fraction ◽  
Numerical Study ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
The Other ◽  
Square Enclosure

The authors of the present paper sought to conduct a numerical study on the convection heat transfer, along with the radiation and entropy generation (EGE) of a nanofluids (NFs) in a two and three-dimensional square enclosure, by using the FVM. The enclosure contained a high-temperature blade in the form of a vertical elliptical quadrant in the lower corner of the enclosure. The right edge of the enclosure was kept at low temperature, while the other edges were insulated. The enclosure was subjected to a magnetic field (MGF) and could be adjusted to different angles. In this research, two laboratory relationships dependent on temperature and volume fraction were used to simulate thermal conductivity and viscosity. The variables of this problem were Ra, Ha, RAP, nanoparticle (NP) volume fraction, blade aspect ratio, enclosure angles, and MGF. Evaluating the effects of these variables on heat transfer rate (HTR), EGE, and Be revealed that increasing the Ra and reducing the Ha could increase the HTR and EGE. On the other hand, adding radiation HTR to the enclosure increased the overall HTR. Moreover, an augmentation of the volume fraction of magnesium oxide NPs led to an increased amount of HTR and EGE. Furthermore, any changes to the MGF and the enclosure angle imposed various effects on the HTR. The results indicated that an augmentation of the size of the blade increased and then decreased the HTR and the generated entropy. Finally, increasing the blade always increased the Be.

scholarly journals Effect of Hydromagnetic Mixed Convection Double Lid-Driven Square Cavity with Inside Elliptic Heated Block

2017 ◽  
Vol 9 (1) ◽  
pp. 1-11
Author(s):  
M. J. H. Munshi ◽  
M. A. Alim
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Mixed Convection ◽  
Convection Heat Transfer ◽  
Square Cavity ◽  
Left Wall ◽  
Grashof Number ◽  
Mixed Convection Heat Transfer ◽  
The Right ◽  
The Magnetic Field

Mixed convection heat transfer in a two-dimensional the effect of hydromagnetic mixed convection in a double lid driven square cavity with inside elliptic heated block is studied numerically. The left wall of the square cavity and inside the elliptic block was  kept at Th while the right wall  of the square cavity at a cold temperature Tc with Th > Tc. The lid is assumed to be upper wall moving in left to right and lower wall right to left directions respectively. The magnetic field of strength B is applied parallel to x- axis. Result is presented firstly for different Reynolds number (50 ? Re ? 150), Prandtl number Pr= 0.733 and presented for different Grashof number (103 ? Gr ? 106). The numerical results studied the effect of Reynolds number, Grashof number and buoyancy ratio on the local values. It is found that direction of lid and different elliptic heated block are more effective on heat and mass transfer on fluid flow with increasing magnetic field for all studied parameters.

scholarly journals Entropy generation due to the mixed convection flow of MWCNT−MgO/water hybrid nanofluid in a vented complex shape cavity

2020 ◽  
Vol 307 ◽  
pp. 01007
Author(s):  
Mahdi Benzema ◽  
Youb Khaled Benkahla ◽  
Ahlem Boudiaf ◽  
Seif-Eddine Ouyahia ◽  
Mohammed El Ganaoui
Keyword(s):  
Mixed Convection ◽  
Entropy Generation ◽  
Complex Shape ◽  
Volume Fraction ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Convection Flow ◽  
Hybrid Nanofluid ◽  
Bejan Number ◽  
Inclined Plate

This paper reports a numerical study of mixed convection heat transfer with entropy generation in a vented complex shape cavity filled with MWCNT−MgO (15:85 vol %) /water hybrid nanofluid. A hot source is placed at the mid potion of the inclined plate of the enclosure, while the rest of the rigid walls are adiabatic. A thermo-dependent correlations proposed by [12] for the dynamic viscosity and the thermal conductivity, especially developed for the considered fluid, are used. After validation of the model, the analysis has been done for a Reynolds numbers ranging from 10 to 600 and total nanoparticles volume fraction ranging from 0.0 to 0.02 using the finite volume method. The predicted results of streamlines, isotherms, isentropic lines, average Nusselt number, average entropy generation and average Bejan number are the main focus of interest in the present paper.

scholarly journals A 3D numerical simulation of a mixed convection flow in a building integrated photovoltaic thermal (BIPV/T) front

2021 ◽  
Vol 321 ◽  
pp. 03011
Author(s):  
Malika Boufkri ◽  
Btissam Abourida ◽  
Smaine Kouidri ◽  
Mohamed Sannad ◽  
Lahoucine Belarche
Keyword(s):  
Heat Transfer ◽  
Mixed Convection ◽  
Numerical Study ◽  
Three Dimensional ◽  
Solar Panel ◽  
Convection Flow ◽  
Mixed Convection Flow ◽  
Thermal Front ◽  
Left Wall ◽  
Building Integrated Photovoltaic

In the present paper, a numerical study of mixed convection flow of a three-dimensional building integrated photovoltaic thermal front (BIPV/T) has been investigated. The configuration consists of a cubical system heated by a solar panel partition. The left wall has an inlet damper at the bottom allowing the cold air flotation in a gap between the solar panel and the opposite vertical insulated wall. The finite volume method is used to analyze the dynamic, thermal fields and the heat transfer flow of the system. The results revealed that the heat transfer rate is affected by Reynolds and Nusselt number’s variations.

scholarly journals Three-dimensional mixed convection heat transfer in a partially heated ventilated cavity

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 1895-1907
Author(s):  
Hicham Doghmi ◽  
Btissam Abourida ◽  
Lahoucin Belarche ◽  
Mohamed Sannad ◽  
Meriem Ouzaouit
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Convection Heat Transfer ◽  
Heat Transfer Process ◽  
Heating Section ◽  
Ventilated Cavity ◽  
Section Dimension

The 3-D mixed convective heat transfer inside a ventilated cavity partially heated is studied numerically by using control volume method. The heating square portion similar to the integrated electronic devices is placed on the left vertical wall of the enclosure. The right vertical wall is maintained at ambient temperature and all other walls are adiabatic. The results are presented in terms of flow structures, temperature distribution, and global average Nusselt number for various combinations of thermal controlling parameters, namely, the Richardson number (0 ? Ri ? 10), the Reynolds number (10 ? Ri ? 200), the heating section dimension (0. ? ? ? 0.7), and the relative height of the openings B = h/L = 1/8. It is found that for the low Reynolds number the heat transfer process is carried out only by conduction. On the other hand, the highest thermal performance is achieved by reducing the heating section dimension.

Magnetic Field Effect on Mixed Convection in Lid-Driven Trapezoidal Cavities Filled With a Cu–Water Nanofluid With an Aiding or Opposing Side Wall

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Ali J. Chamkha ◽  
Muneer A. Ismael
Keyword(s):  
Magnetic Field ◽  
Mixed Convection ◽  
Volume Fraction ◽  
Magnetic Field Effect ◽  
Side Wall ◽  
Cu Nanoparticles ◽  
Suppression Effect ◽  
Side Walls ◽  
The Right ◽  
The Magnetic Field

The present study investigates mixed convection inside a Cu–water nanofluid filled trapezoidal cavity under the effect of a constant magnetic field. The mixed convection is achieved by the action of lid-driving of the right hot inclined side wall in the aiding or the opposing direction. The left inclined side wall is fixed and kept isothermal at a cold temperature. The horizontal top and bottom walls are fixed and thermally insulated. The magnetic field is imposed horizontally. The problem is formulated using the stream function-vorticity procedure and solved numerically using an efficient upwind finite-difference method. The studied parameters are: the Richardson number Ri = (0.01–10), the Hartman number Ha = (0–100), the volume fraction of Cu nanoparticles φ = (0–0.05), and the inclination angle of side walls Φ = (66 deg, 70 deg, 80 deg). The results have shown that the suppression effect of the magnetic field for the aiding case is greater than that for the opposing case. Meanwhile, the enhancement of the Nusselt number due to the presence of the Cu nanoparticles is greater for opposing lid-driven case.

Magnetohydrodynamic Mixed Convection of a Cu-Water Nanofluid in a Vertical Channel

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
A. Raisi ◽  
S. M. Aminossadati ◽  
B. Ghasemi
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Convection Heat Transfer ◽  
Vertical Channel ◽  
Mixed Convection Heat Transfer

This technical brief numerically examines the mixed convection heat transfer of a Cu-water nanofluid in a parallel-plate vertical channel that is influenced by a magnetic field. An upward flow of Cu-water nanofluid enters the channel at a relatively low temperature and a uniform velocity. It is found that the magnetic field has dissimilar effects on the heat transfer rate at different Richardson numbers. The increase of solid volume fraction results in an increase of the heat transfer rate especially at low Richardson numbers.

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