Laminar Free Convection in a Square Enclosure Driven by the Lorentz Force

Abstract

A numerical study is presented of laminar free convection flow driven by magnetic forces. An external magnetic field with one spatially varying component is applied to an electrically conducting fluid in a square enclosure. This magnetically-driven flow is controlled by the intensity and the wave number of the applied magnetic forcing. In addition, when the enclosure is heated laterally in a non-zero gravity environment, the resulting buoyant forces may contribute or resist the magnetically-driven fluid motion. The present results show that a strong magnetic field can even reverse the buoyant flow. The circulation intensity of the flow and the heat transfer from the sidewalls is increased with increasing magnetic field or with decreasing magnetic Reynolds number. The wave number of the magnetic forcing is also an important parameter that determines the vortex patterns and, consequently, the convection heat transfer.

The suggestion of Prof. Daniele Carati of ULB to focus on MHD fluid flows driven by a nonuniform magnetic field is gratefully acknowledged. The authors also thank Dr. Alkis Grecos for fruitful discussions. This work was performed in the framework of the EURATOM—Hellenic Republic Association and is supported by the European Union within the Fusion Program. The content of this publication is the sole responsibility of the authors and it does not necessarily represent the views of the Commission or its services.