Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Numerical Simulations of Natural Convection and Surface Radiation in an Open Cavity With Disconnected Solid Blocks
Submission Author:
Vanessa Glück Nardi , PR
Co-Authors:
Alan Lugarini de Souza, Admilson Franco, Vanessa Glück Nardi
Presenter: Vanessa Glück Nardi
doi://10.26678/ABCM.COBEM2017.COB17-2429
Abstract
Several studies have been conducted on natural convection in heterogeneous porous media. The majority of them have in common the hypothesis of negligible heat transfer by radiation. Recent investigations have shown that surface radiation plays an important role on the overall heat transfer in cavities subject to natural convection. In this study, numerical methods are used to solve natural convection and surface radiation in an open cavity containing several disconnected and conducting solid blocks. The cavity vertical wall is isothermally heated while in the other end, it is opened to a fluid reservoir. The horizontal walls are kept adiabatic. The blocks are squared, equally spaced, disconnected, and heat conducting, with fluid-to-solid thermal conductivity ratio set as unity. The fluid properties are assumed constant except for the buoyancy term in which is used the Oberbeck-Boussinesq approximation. The cavity and block surfaces are grey, opaque and diffuse, with surface emissivity set as unity. The effect of varying the Rayleigh number from 10^3 to 10^8, and the number of blocks from 9 to 144, at fixed porosity of 64%, are investigated. The average convective and radiative Nusselt numbers are evaluated and the convective and radiative drop phenomena are discussed.
Keywords
Natural Convection, thermal radiation, Open cavity flow, heterogeneous media
