Heat-flux-enhanced thermoelectric self-driven flow of liquid metal in an annular channel

A temperature gradient across dissimilar metals can induce a thermoelectric effect, which in turn drives the flow of liquid metal under a magnetic field. In this study, a thermoelectric self-driven liquid metal flow was realized using gallium–indium–tin and constantan, achieving a maximum velocity of 0.2 m/s. The flow behavior was systematically investigated. In the weak magnetic field regime, the flow accelerates with increasing magnetic field strength and heat flux, and a pronounced near-bottom higher velocity forms at the bottom. In the strong magnetic field regime, however, the enhancement of induced current leads to dominant Lorentz damping, resulting in a more uniform velocity profile. The variation of average flow velocity with the Hartmann number (Ha) exhibits a single-peak behavior characterized by “enhancement at low fields and suppression at high fields,” revealing the dual role of the magnetic field. Heat flux consistently promotes the flow, with the maximum average flow rate showing a linear dependence on the temperature difference, while the optimal Hartmann number (Haopt) increases in a nonlinear manner. Finally, a segmented predictive model based on dimensionless heat flux, the thermoelectric number (Te), and the Ha was proposed, achieving a fitting accuracy of over 92%. This model effectively characterizes the velocity evolution governed by the competition between thermoelectric driving and magnetic damping. The present study not only elucidates the fundamental mechanisms of thermoelectric magnetohydrodynamic flow but also provides theoretical and experimental support for the application of liquid metals in energy storage and thermal management.