EXPERIMENT ON THE THERMOCAPILLARY CONVECTION OF A MERCURY LIQUID BRIDGE IN A FLOATING HALF ZONE

A liquid bridge of a floating half zone consisting of liquid mercury s ealed in a glass tube with nitrogen atmosphere was used for the experi ment of thermocapillary convection with a low Prandtl number liquid. A non-contacted diagnostic method was developed to monitor the surface flow and the surface oscillation. A growing surface film (or skin) is a crucial source to suppress thermocapillary convection, and is discus sed in this paper. For the case of a mercury Liquid bridge, the critic al Marangoni number was obtained as 900, and the oscillatory frequency was around 5 Hz.