Natural convection flows in cavities

by E. P. R. Smith

Publisher: University of Birmingham in Birmingham

Written in English
Published: Downloads: 311
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Edition Notes

Thesis (Ph.D.) - University of Birmingham, Dept of Chemical Engineering.

Statementby E.P.R. Smith.
ID Numbers
Open LibraryOL13889300M

The problem of Magnetohydrodynamic (MHD) free convection heat transfer in a square open cavity containing a heated circular cylinder at the centre has been investigated in this work. As boundary conditions of the cavity, the left vertical wall is kept at a constant heat flux, bottom and top walls are kept at different high and low temperature by: 4. Buoyancy-driven airflow that included two isothermal inner plates established in a vented cavity is investigated numerically. The thermally optimum wall-to-wall spacing of the immersed channel, as well as its dependence with respect to the relevant governing parameters, are determined. Results are presented as a function of the aspect ratio b/H for a wide range of Rayleigh numbers RaH. Flow and temperature fields. The buoyancy-driven flow and temperature fields in the enclosure for a cold plate and a hot plate with the variation of location ratios a/H and b/H are illustrated by means of contour maps of streamlines and isotherms, respectively, as exemplified in Figs. 3 to For Fig.3 (a-f), there are two vortices flow where the directions are different for cold plate Cited by: 1. de Vahl Davis, G., and Jones, I. P., , “The Effect of Vertical Temperature Gradients on Multi-cellular Flows in High Aspect Ratio Cavities,” Proc. Conference on Liquid Metal Technology in Energy Production, Oxford, United Kingdom, pp. 9–Cited by:

Natural Convection – Heat Transfer. Similarly as for forced convection, also natural convection heat transfer take place both by thermal diffusion (the random motion of fluid molecules) and by advection, in which matter or heat is transported by the larger-scale motion of currents in the fluid. At the surface, energy flow occurs purely by conduction, even in convection. Natural convection in a rectangular porous cavity with constant heat flux on one vertical wall F. A. / Natural convection in a rectangular porous cavity with constant heat flux on one vertical wall. In: Journal of Heat Transfer. ; Vol Flow patterns are observed to be quite different from those in the case of a cavity with both Cited by: The onset of natural convection in a 2D air filled cavity open at the top with adiabatic side walls is studied. The numerical model shows the existence of weak convective flow near the top corner of a cavity due to the thermal gradient between the walls and the atmosphere even at low Rayleigh numbers, as also confirmed by the interferometry-based experimental by: 6. Steady natural convection flows in a square cavity with linearly heated side wall(s).

Flow patterns of two-dimensional natural convection in a vertical air-filled tall cavity with differentially heated sidewalls are investigated. Numerical simulations based on a finite difference method are carried out for a wide range of Rayleigh numbers and aspect ratios from the onset of the steady multicellular flow, through the reverse transition to the unicellular pattern, to the unsteady Cited by: Timothy A. Dunn and Rose C. McCallen, Parallel computations of natural convection flow in a tall cavity using an explicit finite element method, International Journal for Numerical Methods in Fluids, 40, 8, (), ().Cited by:   The problem of transient natural convection in a cavity of aspect ratio A [les ] 1 with differentially heated end walls is considered. Scale analysis is used to show that a number of initial flow types are possible, collapsing ultimately onto two basic types of steady flow, determined by the relative value of the non-dimensional parameters describing the by: This paper investigates the entropy generation and natural convection inside a C-shaped cavity filled with CuO-water nanofluid and subjected to a uniform magnetic field. The Brownian motion effect is considered in predicting the nanofluid properties. The governing equations are solved using the finite volume method with the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) by:

Natural convection flows in cavities by E. P. R. Smith Download PDF EPUB FB2

Abstract: Unsteady natural convection laminar flows in a square cavity formed by insulated bottom Natural convection flows in cavities book top walls, uniformly heated left wall and cooled right wall has been investigated.

The governing equations are transformed into a non-dimensional form and the resulting partial differential equations are solved numericallyCited by: 2.

natural convection, laminar flow, upright-angled triangular cavity, steady-state, finite element method. Introduction. Buoyancy induced flows inside enclosures is an active research field due to its prac-tical application in nature, science and engineering. The basic topics of the subject are usuallyFile Size: KB.

The present study focuses on natural convection in rectangular cavities with one active vertical wall. The cavity is closed, filled with air and cooled from one side with a local heat sink.

Heat transfer is pure natural convection because radiation is by: Request PDF | Isothermal and natural convection flows in fractal cavities | In the present work the dynamics of a fluid flow in a fractal domain is analyzed.

This domain is a cavity in which the. natural convection in rectangular cavities to examine the effects of heater dimensions and location, aspect ratio, and boundary conditions on this cavity.

November and Nansteel () studied natural convective flow in a square cavity with one cooled vertical wall and a heated base. Poulikakos (). convection flows in a cavity filled with air and heated from below. One of the v ertical walls has a cold portion, while the other walls a re adiabatic.

This cavity simulates a living space with. the heat transfer and flow characteristics in the cavity but no trapped fluid phenomenon was captured.

In this paper we present a numerical study of natural convection in an air filled partitioned square cavity. The cavity was differentially heated and to its top and its bottom walls a. Natural convection in air cavities has been the subject of much research in recent decades due to its various engineering applications, such as solar chimneys, double skin façades, and Trombe walls.

Natural convection in triangular enclosures is an important problem. It displays well the generic attributes of this class of convection, with its dependence on enclosure geometry, orientation and thermal boundary conditions.

It is particularly rich in its variety of flow regimes and thermal fields as well as having significant practical Cited by:   Application: Natural Convection in a Square Cavity. For our example, we will use a model that couples the Navier-Stokes equations and the heat transfer equations to model natural convection in a square cavity with a heated wall.

The temperature on the left and right walls is K and K, respectively. Home Browse by Title Periodicals Applied Numerical Mathematics Vol. 47, No. Isothermal and natural convection flows in fractal cavities article Isothermal and natural convection flows in fractal cavitiesAuthor: DoescherErwin, F de Campos VelhoHaroldo, M RamosFernando.

Natural-Convection Flows in Air-Filled, Differentially Heated Cavities with Adiabatic Horizontal Walls Article (PDF Available) in Numerical Heat Transfer Applications 50(5) July Section II, Department of Chemical Engineering, National Technical University of Athens, AthensGreece.

SUMMARY Numerical simulations have been undertaken for the benchmark problem of natural convection flow in a square cavity. The conjugate natural convection of a new type of hybrid nanofluid (Ag–MgO/water hybrid nanofluid) inside a square cavity is addressed.

A thick layer of conductive solid is considered over the hot wall. The governing partial differential equations (PDEs) representing the physical model of the natural convection of the hybrid nanofluid along with the boundary conditions are by: 8.

The corresponding boundary‐domain integral equations are presented along with discussions of the kinetics and kinematics of the fluid flow problem. The boundary‐domain integral formulation is developed and tested for natural convection flows in closed cavities with complex by: Natural convective flow of air inside the cubical cavity is investigated numerically.

The temperature of the bottom wall is kept higher than that of top cold wall, and other four walls are assumed. Numerical simulations have been undertaken for the benchmark problem of natural convection flow in a square cavity. The control volume method is used to solve the conservation equations for laminar and turbulent flows for a series of Rayleigh numbers (Ra) reaching values up to 10 The k‐ϵ model has been used for turbulence modelling with and without logarithmic wall functions.

Transient natural convection in a cavity with heat input and a constant temperature wall on opposite sides. International Journal of Heat and Fluid Flow, Vol.

14, Issue. 4, p. International Journal of Heat and Fluid Flow, Vol. 14, Issue. 4, p. Cited by: Aydin et al. () and Sarris et al. () have indicated that there exist only a limited amount of works published on convective flow in fluid-filled cavities (non-porous medium) with a more complex case of cooling from the top wall, mainly with periodic temperature conditions Author: Aroon Shenoy, Mikhail Sheremet, Ioan Pop.

Lattice Boltzmann Computations of Natural Convection Heat Transfer of Nanofluid in a Square Cavity Heated by Protruding Heat Source J. Thermal Sci. Eng. Appl (August, ) Lattice Boltzmann Method for Combined Natural Convection Surface Radiation in Open CavityCited by: 5.

We numerically study the three-dimensional magnetohydrodynamics (MHD) stability of oscillatory natural convection flow in a rectangular cavity, with free top surface, filled with a liquid metal, having an aspect ratio equal to A=L/H=5, and subjected to a transversal temperature gradient and a uniform magnetic field oriented in x and z directions.

The finite volume method was used in order to Author: M. Battira, R. Bessaih. An experimental investigation of heat transfer by natural convection from a smooth, isothermal cubic cavity with a variety of side-facing apertures is described in this paper. The study was motivated by the desire to predict the convective loss from large solar thermal-electric receivers and to understand the mechanisms which control this by: Natural-convection flows in air-filled, differentially heated cavities with adiabatic horizontal walls.

In such conditions natural convection has a significant impact on the heat balance at the solid—liquid boundary that develops into the unfrozen layer. The goal of this study is to develop a one-dimensional model which is capable of predicting the transient response of the ice-layer to a prescribed cooling temperature variation.

Prasad, A., Koseff, J.: Combined forced and natural convection heat transfer in a deep lid-driven cavity flow. Int. Heat Fluid F – () CrossRef Google ScholarAuthor: Dhrubajyoti Kashyap, Anoop K. Dass. Rayleigh–Bénard cells.

Natural convection is a type of flow, of motion of a liquid such as water or a gas such as air, in which the fluid motion is not generated by any external source (like a pump, fan, suction device, etc.) but by some parts of the fluid being heavier than other parts. Natural convection flows were analyzed both experimentally and numerically for two different horizontal thermoacoustic cavities, when no acoustic oscillations were present.

The first cavity consisted of a cylindrical resonator filled with air and containing a thermoacoustic core made of a ceramic stack placed next to a wire resistance (hot heat exchanger).Author: Omar Hireche, Islam Ramadan, Catherine Weisman, Catherine Weisman, Hélène Bailliet, Yann Fraigneau.

Research into thermal convection in porous media has substantially increased during recent years due to its numerous practical applications. These problems have attracted the attention of industrialists, engineers and scientists from many very diversified disciplines, such as applied mathematics, chemical, civil, environmental, mechanical and nuclear engineering, geothermal physics and food.

Buy Natural Convection From An Open Rectangular Cavity With Cylinder: Natural Convection From An Open Rectangular Cavity Containing A Heated Circular Cylinder on FREE SHIPPING on qualified orders. In the past few decades, natural convection flow in a square cavity with differentially heated vertical walls and adiabatic horizontal walls has been studied extensively due to its fundamental importance in the understanding of buoyancy-driven flows and its relevance to a wide range of engineering applications, such as in cooling of nuclear reactors, air conditioning of rooms, cooling of electronic equipment, crystal growing of liquids, solar energy collector Cited by: 6.

The natural convection heat losses occurring from cubical open cavities are analysed in this paper. Open cubical cavities of sides m, m, m, m, and 1 m with constant temperature back wall boundary conditions and opening ratio of 1 are studied.

The Fluent CFD software is used to analyse the three-dimensional (3D) cavity by: 9. Discussion on the paper “Investigation of Double Diffusive Natural Convection in Presence of Gray Gas Radiation Within a Square Cavity Using Multiple Relaxation Time Lattice Boltzmann Method, F.

Moufekkir, M.A. Moussaoui, A. Mezrhab, J.P. Fontaine, M. Bouzidi, Journal of Heat TransferVol. /”Cited by: NUMERICALSTUDYOFNATURALCONVECTION sorypoint,wallandglobalsolutionresults. Meshof20×elements Meshof24×elements Quantity Ave.

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