Stability of the Boiling Two-Phase Flow of a Magnetic Fluid

Abstract

Elucidation of magnetic stabilization of boiling two-phase flow by utilizing the magnetization of the fluid is proposed herein. The effect of magnetic field on the stability of the boiling two-phase pipe flow of the magnetic fluid under a nonuniform magnetic field is investigated both theoretically and experimentally. First, governing equations of boiling two-phase flow based on the unsteady thermal nonequilibrium two-fluid model are presented and analytically solved using a linearization method. The analytical results on stabilization are then inspected experimentally using an experimental apparatus composed of a small test loop. Results of the analytical study on the void waves, show that the stabilization of two-phase flow can be obtained by practical use of the magnetic body force acting on the fluid and by applying the appropriate superficial gas-phase velocity. Those results also show that magnetic stabilization is obtained because the two-phase magnetic body force enhances the diffusion effect of the void waves. It is experimentally clarified that the two-phase flow state can be stabilized and homogenized by magnetization of the fluid and that vapor bubbles can be minutely produced by effective use of the magnetic body force. The axial magnetic field is more effective for stabilization and homogenization of the two-phase magnetic fluid flow than the transverse magnetic field.