Surface waves of liquid metal film flow under the influence of spanwise magnetic field

The present paper focuses on the investigation of the surface wave of liquid GaInSn film which flows along a non-electric conductivity surface in the presence of a spanwise magnetic field. Using the high-speed camera with frame rate 1000 1/s, we experimentally observed the time-varying surface waves at different Reynolds number and Hartmann number. Furthermore, we also extracted the gray value from two fixed lines in photos to show the wave information quantitatively along the streamwise direction and spanwise direction. Experimental results show that the present spanwise direction magnetic field plays an important role in the regularization of film surface waves, namely when gradually increasing the strength of magnetic field, the random surface waves can be firstly damped along the direction of magnetic field and then strongly inhibited due to the induced Lorentz force. The decreasing of wave velocity also indicates that the spanwise magnetic field has a stabilizing effect on the film flow.