Heat Transfer Enhancement of Pulsating Flow in an Open Cavity Subjected to Uniform Magnetic Field

Resumo

The present numerical work is devoted to the effect of an external magnetic field on a pulsating flow through an open cavity in a horizontal channel. The cavity is heated uniformly from the bottom wall. The finite volume method is used to solve the energy and Navier—Stokes equations. At the inlet of the channel flow pulsations are produced by adding a sinusoidal component to the velocity. The investigation is conducted for different Strouhal (0 ≤ St ≤1), Richardson (0.25 ≤ Ri ≤1), and Hartmann numbers (0 ≤ Ha ≤50) and for various aspect ratios of the cavity (L/H = 1, 1.5, and 2) at a pulsation amplitude A = 0.1. Various characteristics of the flow, such as isotherms, streamlines, and average and normalized Nusselt numbers are presented. The results indicate that the influence of the external magnetic field on the temperature distribution, flow field, heat transfer mode, and heat transfer enhancement rate vary with the Hartmann number. The effect of pulsations on the heat transfer enhancement is well correlated with the magnetic field intensity, Richardson number, and aspect ratio of the cavity.