Numerical Calculation on Magnetohydrodynamic Two-Phase Annular Flow in Circular Pipe Liquid-Phase Velocity Distribution and Two-Phase Flow Pressure Drop

Abstract

A numerical calculation model for a magnetohydrodynamic (MHD) two-phase annular flow has been proposed in order to study the characteristics of flow qualities, such as induced electric current distribution, liquid-phase velocity distribution and two-phase flow pressure drop, in a liquid-metal two-phase flow through a circular pipe under a transverse magnetic field for the region of high qualities (or high void fractions). It has become clear that the liquid-phase velocity distribution and thus the resulting two-phase flow pressure drop are determined mainly by the gas-phase flow velocity and the electromagnetic force, which is generated by a vector product of the induced current and the applied magnetic field. The calculation model has predicted a liquid velocity distribution with a large change in the circumferential direction. The liquid velocity is almost flat from the gas-liquid interface to the wall at a circumferential angle parallel to the applied magnetic field, and the velocity changes from a large value at the interface to zero at the wall at a circumferential angle perpendicular to the magnetic field. The calculation model has also predicted that the MHD pressure drop of the two-phase annular flow becomes a little larger than that of the corresponding single-phase liquid flow under the conditions of the same magnetic field and the same liquid flow rate.

KEYWORDS:

• magnetohydrodynamics
• MHD
• magnetic fields
• liquid metals
• two-phase flow
• annular flow
• flow rates
• pressure drop
• Hartmann number
• circular pipe
• numerical calculation
• finite difference method