Numerical Analysis of the Effects of Selected GeometricaludParameters and Fluid Properties on MHD Natural ConvectionudFlow in an Inclined Elliptic Porous Enclosure withudLocalized Heating

摘要

Magnetohydrodynamic (MHD) natural convection flow and associated heatudconvection in an oriented elliptic enclosure has been investigated with numericaludsimulations. A magnetic field was applied to the cylindrical wall of the configuration,udthe top and bottom walls of the enclosure were circumferentially cooled andudheated, respectively, while the extreme ends along the cross-section of the ellipticudduct were considered adiabatic. The full governing equations in terms of continuity,udmomentum, and energy transport were transformed into nondimensional formudand solved numerically using finite difference method adopting Gauss–Seidel iterationudtechnique. The selected geometrical parameters and flow properties consideredudfor the study were eccentricity (0, 0.2, 0.4, 0.6, and 0.8), angle of inclination (0°,ud30°, 60°, and 90°), Hartmann number (0, 25, and 50), Grashof number (104, 105,udand 106), and Darcy number (10−3, 10−4, and 10−5). The Prandtl number was heldudconstant at 0.7. Numerical results were presented by velocity distributions as well asudheat transfer characteristics in terms of local and average Nusselt numbers (i.e., rateudof heat transfer). The optimum heat transfer rate was attained at e value of 0.8. Also,udthe heat transfer rate increased significantly between the angles of inclination 58°udand 90°. In addition, Hartmann number increased with decreased heat transfer rateudand flow circulation. A strong flow circulation (in terms of velocity distribution) wasudobserved with increased Grashof and Darcy numbers. The combination of the geometricudand fluid properties thereforHeat Trans Asian Res, 00(0): 1–33, 2016; Published online in Wiley Online Libraryud(wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21211e can be used to regulate the circulation and heatudtransfer characteristics of the flow in the enclosure. C⃝ 2016 Wiley Periodicals, Inc.