Flow and heat transfer past row of magnetic obstacles for various separation ratios

Abstract

This paper presents the effect of the spacing between the magnetic obstacles on the overall transport processes at interaction parameter N=11 and Reynolds number Re=600. The numerical simulations are performed for separation ratio (spacing to magnet width ratio), g⁎, of 1.0, 1.25, 1.5 1.75, 2.0, 2.25, 2.5 and 3.0 in a staggered grid system. No significant interaction between the wakes is observed for g⁎≥2.25. However, at smaller separation ratio (such as, g⁎=1.0), the wakes interact in a complicated manner resulting in different thermo-hydrodynamic regimes. Moreover, the convection effect is much stronger than absent magnetic obstacles situation for all separation ratios, and the maximum value of overall heat transfer increment is about 52.3% at g⁎=1.0. The optimum separation ratio for heat transfer enhancement is g⁎=2.0 with only a modest increase in friction loss.