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Journal ArticleDOI

On the effect of porous thick horizontal partial partition attached to one of the active walls of a differentially heated square cavity

01 May 1994-International Journal of Numerical Methods for Heat & Fluid Flow (MCB UP Ltd)-Vol. 4, Iss: 5, pp 399-411
TL;DR: In this article, the effect of a horizontal partial porous partition on heat transfer and flow structure in a differentially heated square cavity is investigated, where the fluid flow is assumed to be governed by Navier-Stokes equations and fluid saturated porous media is governed by Darcy's equations.
Abstract: The effect of a horizontal partial porous partition on heat transfer and flow structure in a differentially heated square cavity is investigated. While the fluid flow is assumed to be governed by Navier—Stokes equations, fluid saturated porous media is assumed to be governed by Darcy’s equations. Standard Galerkin method of finite element formulation is applied for discretization of the system of equations. The non‐linearities in the discretized equations are treated with Newton‐Raphson scheme. The code developed is tested for validation for modified Rayleigh number Ra up to 400. The code is then applied to a differentially heated square cavity with a horizontal partial porous partition. While the thickness of the porous partition is found to have appreciable effect on heat transfer and flow field, width of the porous partition is found to have insignificant bearing on heat transfer except when the partition is very small and compatible to the thickness of the boundary layer developed. During the experime...
Citations
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Journal ArticleDOI
TL;DR: In this article, a new lattice Boltzmann (LB) approach was developed to overcome the difficulty of conjugate problems on fluid-porous interfaces, which is validated by three benchmark tests.

33 citations

Journal ArticleDOI
TL;DR: In this article, the authors provided a numerical study of conjugate heat transfer by mixed convection and conduction in a lid-driven enclosure with thick vertical porous layer, and the effect of the relevant parameters: Richardson number (Ri=0.1, 1, 10, 100) and thermal conductivity ratio (Rk = 0.
Abstract: Purpose – The purpose of this paper is to provide a numerical study of conjugate heat transfer by mixed convection and conduction in a lid-driven enclosure with thick vertical porous layer. The effect of the relevant parameters: Richardson number (Ri=0.1, 1, 10) and thermal conductivity ratio (Rk=0.1, 1, 10, 100) are investigated. Design/methodology/approach – The studied system is a two dimensional lid-driven enclosure with thick vertical porous layer. The left vertical wall of the enclosure is allowed to move in its own plane at a constant velocity. The enclosure is heated from the right vertical wall isothermally. The left and the right vertical walls are isothermal but temperature of the outside of the right vertical wall is higher than that of the left vertical wall. Horizontal walls are insulated. The governing equations are solved by finite volume method and the SIMPLE algorithm. Findings – From the finding results, it is observed that: for the two studied cases, heat transfer rate along the hot wa...

6 citations

Journal ArticleDOI
TL;DR: In this paper , the authors presented the numerical analysis of exergy transfer and irreversibility through the discrete filling of high-porosity aluminum metal foams inside the horizontal pipe.
Abstract: Purpose This study aims to present the numerical analysis of exergy transfer and irreversibility through the discrete filling of high-porosity aluminum metal foams inside the horizontal pipe. Design/methodology/approach In this study, the heater is embedded on the pipe’s circumference and is assigned with known heat input. To enhance the heat transfer, metal foam of 10 pores per inch with porosity 0.95 is filled into the pipe. In filling, two kinds of arrangements are made, in the first arrangement, the metal foam is filled adjacent to the inner wall of the pipe [Model (1)–(3)], and in the second arrangement, the foam is located at the center of the pipe [Models (4)–(6)]. So, six different models are examined in this research for a fluid velocity ranging from 0.7 to7 m/s under turbulent flow conditions. Darcy Extended Forchheimer is combined with local thermal non-equilibrium models for forecasting the flow and heat transfer features via metal foams. Findings The numerical methodology implemented in this study is confirmed by comparing the outcomes with the experimental outcomes accessible in the literature and found a fairly good agreement between them. The application of the second law of thermodynamics via metal foams is the novelty of current investigation. The evaluation of thermodynamic performance includes the parameters such as mean exergy-based Nusselt number (Nue), rate of irreversibility, irreversibility distribution ratio (IDR), merit function (MF) and non-dimensional exergy destruction (I*). In all the phases, Models (1)–(3) exhibit better performance than Models (4)–(6). Practical implications The present study helps to enhance the heat transfer performance with the introduction of metal foams and reveals the importance of available energy (exergy) in the system which helps in arriving at optimum design criteria for the thermal system. Originality/value The uniqueness of this study is to analyze the impact of discrete metal foam filling on exergy and irreversibility in a pipe under turbulent flow conditions.
References
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Journal ArticleDOI
TL;DR: In this article, the authors compared the empirical formulas recommended by McAdams (1955) for a heated horizontal plate facing upward with the data of the composite surface and found the coefficients that best fit the data.
Abstract: Test data are correlated in Fig. 2 in the form of a Nu versus Ra graph with the diameter of the heating surface as the char­ acteristic length. Included for comparison are the empirical formulas recommended by McAdams (1955) for a heated hor­ izontal plate facing upward. Fixing the exponents based on the McAdams recommendations, one finds the coefficients that best fit the data of the composite surface. This yields: Nu = 1.125 Ra1/4 for 10 4

61 citations

Journal ArticleDOI
TL;DR: The effect of nonuniform permeability and thermal diffusivity on natural convection through a porous system heated from the side is investigated numerically in this paper, where it is shown that the heat transfer rate is influenced substantially by the thickness and permeability of the peripheral sublayers adjacent to the heated vertical walls.

60 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of internal flow obstructions on heat transfer through a 2-dim porous layer heated from the side was investigated and three types of flow obstruction were considered.

60 citations

Journal ArticleDOI
01 Mar 1974
TL;DR: In this paper, the authors describe the convective heat transfer in a vertical space insulated with a permeable material and present a numerical solution to the problem for Ra0 ⩽ 200, which is the range of interest to building technologies.
Abstract: This article describes the natural convective heat transfer in a vertical space insulated with a permeable material. A numerical solution to the problem is given for Ra0 ⩽ 200, which is the range of interest to building technological applications. The variables and boundary conditions and their influence upon the convective heat transfer are discussed. Comparisons are made with previously published results.

58 citations