Numerical simulation of magnetohydrodynamic laminar flow in an electrically conducting circular pipe with V-shaped strips

Jie Mao - Mingliang Jin - Chao Xu

School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China

Abstract
The geometry of a duct cross-section has a significant influence on the velocity distribution and pressure drop of liquid metal flow subjected to a transverse magnetic field. In this paper, liquid metal flows in an electrically conducting circular pipe and in a pipe with V-shaped strips at the inner wall are numerically analyzed using a laminar model by an in-house MHD solver developed in the OpenFOAM environment. Distributions of velocity, induced electric current and pressure drop in three kinds of pipes have been analyzed. The effect of the position and depth of V-shaped strips on the velocity distribution and on the pressure drop have been studied. Numerical results show that V-shaped strips in Roberts layers can change the electric current direction from perpendicular to oblique to the magnetic field. This decreases the Lorentz force in Roberts layers and enhances the intensity of the jets. Velocity jets are observed at the bottom of the V-shaped strips attached to Hartmann layers. Moreover, a low-velocity belt forms in the central region of the fluid. The MHD pressure drop in pipes with V-shaped strips is a little higher than that in a normal circular pipe. The increase of the number and depth of V-shaped strips will increase the MHD pressure drop. The relative difference of the pressure drop coefficient decreases with increasing Hartmann number. The duct cross-section geometry can be used to control MHD flow, and the obtained results can be referenced in the design of the liquid metal blanket. Tables 1, Figs 13, Refs 21.