Terrestrial and microgravity experiments on onset of oscillatory thermocapillary-driven convection in hanging droplets

Thermocapillary-driven convection in a hanging droplet is experimentally investigated under normal- and micro-gravity conditions. A droplet is hung on a heated cylindrical rod facing downward, and another rod cooled is placed just beneath the droplet to create the designated temperature difference between both ends of the droplet. A transition of the flow field from a two-dimensional axisymmetric ‘steady’ flow to three-dimensional time-dependent...