Time-Periodic Cooling of Rayleigh–Bénard Convection

Nasseri, Lyes; Himrane, Nabil; Ameziani, Djamel Eddine; Bourada, Abderrahmane; Bennacer, Rachid

doi:10.3390/fluids6020087

Cited by 5 publications

(4 citation statements)

References 43 publications

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“…In our work, we used the rebound boundary condition [45][46][47][48] to model the adhesion to all walls. We also used the boundary conditions for the imposed velocity type (Zu and He [42]) to model the imposed velocities and temperatures.…”

Section: Boundary Conditionmentioning

confidence: 99%

Analysis of Thermal Performances in a Ventilated Room Using LBM-MRT: Effect of a Porous Separation

et al. 2022

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This article demonstrates the feasibility of porous separation on the performance of displacement ventilation in a rectangular enclosure. A jet of fresh air enters the cavity through an opening at the bottom of the left wall and exits through an opening at the top of the right wall. The porous separation is placed in the center of the cavity and its height varies between 0.2 and 0.8 with three values of thickness, 0.1, 0.2, and 0.3. The heat transfer rate was calculated for different intervals of Darcy (10−6 ≤ Da ≤ 10), Rayleigh (10 ≤ Ra ≤ 106), and Reynolds (50 ≤ Re ≤ 500) numbers. The momentum and the energy equations were solved by the lattice Boltzmann method with multiple relaxation times (LB-MRT). Schemes D2Q9 and D2Q5 were chosen for the velocity and temperature fields, respectively. For porous separation, the generalized Darcy–Brinkman–Forchheimer model was adopted. It is represented by a term added in the standard LB equations. For the dynamic domain, numerical simulations revealed complex flow structures depending on all control parameters. The results showed that the thermal field, mainly in the second compartment, is very dependent on the size and permeability of the porous separation. However, they have no influence on the transfer rate.

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Section: Boundary Conditionmentioning

confidence: 99%

Analysis of Thermal Performances in a Ventilated Room Using LBM-MRT: Effect of a Porous Separation

et al. 2022

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“…In industries, the free air cooling due to RB convection happens from small scale computer chips to large scale processes that controls the quantity of excess heat from the system in order to achieve the longevity of equipment life. Owing to the wide applications, works on natural convection heated from below inside the cavity is found in literature [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Magnetoconvection of nanofluid in a partially heated cavity with isothermal blockage

Nagaraj¹,

Nithyadevi²

2022

J. Appl. Math. Comput. Mech.

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Natural convection characteristics of Al 2 O 3 -water nanofluid in a cavity is investigated numerically under the influence of a inclined magnetic field. The bottom wall is partially heated, and the top wall is cooled and the remaining regions of the cavity are kept adiabatic. An isothermally heated square blockage of the different rectangular size is placed at the centre of the cavity. The schematic model is converted into mathematical form, and the non-dimensional equations are discretized by the finite volume method using power law scheme and solved by Semi-Implicit Method for Pressure Linked Equation algorithm. The relevant parameters such as Rayleigh number (10 4 -10 6 ), Hartmann number (10-500), size of blockage ratio (0.25-0.75), length of the heat source (0.25-1.0) and inclination angle of the magnetic field (0 • -90 • ) on the flow and temperature fields are examined. Results are presented in terms of streamlines, isotherms, velocity profile, local and average Nusselt number. It was found that for low Hartmann numbers, the average heat transfer rate attained the maximum at the inclined magnetic field of γ = 45 • . In addition, the blockage ratio of B = 0.75 enhanced the higher heat transfer rate for all values of γ.

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“…The first part of this collection [1][2][3] focuses on a very classical problem, generally falling under the heading of Rayleigh-Bénard convection (RB), that is, the behavior of fluid systems heated from below and cooled from above. In particular, the first study [1] finds its motivations in the field of thermal comfort in the building heating and ventilation sector, where thermal control is traditionally implemented via floor heating and/or ceiling cooling; interestingly, the response of RB convection to the application of time-periodic cooling is assessed by means of sophisticated LBM simulations. Thermogravitational convection is still at the root of the following two numerical investigations [2,3], where, however, a shift is implemented in the intended outcomes.…”

mentioning

confidence: 99%