Thermodynamic analysis of mixed convection in a channel with transverse hydromagnetic effect

An analysis has been performed to study the First and Second laws (of thermodynamics) characteristics of flow and heat transfer inside a vertical channel made of two parallel plates under the action of transverse magnetic field. Combined free and forced convection inside the channel is considered. Flow is assumed to be steady, laminar, fully developed of electrically conducting, and heat-generating/absorbing fluid. Both vertical walls are kept isothermal at the same or different temperatures. Governing equations in Cartesian coordinates are first simplified and solved analytically to develop the expressions for velocity and temperature, entropy generation number (N-S), and irreversibility distribution ratio. Velocity, temperature, and entropy generation profiles are presented graphically. Full form of the governing equations are solved numerically using control-volume based finite volume method. Based on the numerical calculations, average entropy generation numbers are calculated for channels with different aspect ratios. Finally, a correlation is proposed which essentially expedite for calculating a geometric parameter (alpha(0)) that will be characterized by minimum irreversibility at a particular value of Gr/Re (ratio of Grashof number and Reynolds number) and M (Hartmann number). (C) 2003 Editions scientifiques et medicales Elsevier SAS. All rights reserved.