A numerical study of three-dimensional natural convection in a horizontal porous annulus with Galerkin method (Q1119129)

A Galerkin scheme is developed to study the three-dimensional natural convection in a fluid-saturated porous annulus heated from the inner surface. In addition to the two-dimensional multiple solutions reported in the authors' previous paper, three-dimensional solutions are obtained; the secondary cells, with streaklines of the three-dimensionally closed co-axial double helices, are found extending along the axial direction in the top region of the annulus. This brings about an increased maximum local heat transfer coefficient, which consequently enhances overall heat transfer compared with that for the two-dimensional unicellular flow.