vibrational effect on entropy generation in a square porous cavity振动熵影响一代广场多孔腔.pdfVIP

Entropy 2003, 5, 366–376 Entropy ISSN 1099-4300 /entropy/ Vibrational Effect on Entropy Generation in a Square Porous Cavity 1 2 Shohel Mahmud and Roydon Andrew Fraser 1Department of Mechanical Engineering, University of Waterloo, Waterloo, Ontario Canada. Tel. +1 519 888 4567; Fax +1 519 888 6197; Email: smahmud@uwaterloo.ca 2Email: rafraser@uwaterloo.ca Received: 7 December 2002 / Accepted: 10 June 2003 / Published: 31 December 2003 Abstract: We investigate the nature of entropy generation for natural convection in a two- dimensional square section enclosure vibrating sinusoidally perpendicular to the applied temperature gradient in a zero-gravity field. The enclosure is assumed to fill with porous media. The Darcy momentum equation is used to model the porous media. The full governing differential equations are simplified with the Boussinesq approximation and solved by a finite volume method. Whereas the Prandtl number Pr is fixed to 1.0. Results are presented in terms of average Nusselt number (Nuav), entropy generation number (Nsav), Bejan number (Beav), and kinetic energy (KEav). Keywords: vibrational convection, entropy generation, porous media, Bejan number, square cavity. Introduction Free convection heat transfer inside a square cavity (porous or non-porous) is a well-established problem. During last two decades, a vast number of articles have been published in this field. For a comprehensive reference see Bejan