Effect of liquid bridge form on oscillatory thermocapillary convection under 1 g and μg conditions

Abstract

This study analyses the effect of temperature difference between hot and cool disk (Δ T), and non-dimensional liquid bridge volume ( V/ V o) on the transition process from steady thermocapillary convection to periodic or chaotic thermocapillary convection in a liquid bridge modeled after the floating zone method under normal gravity and microgravity conditions. From normal gravity and drop shaft experiments, the difference of the regime of the steady state and the oscillatory state was clarified on the Δ T− V/ V o plane under 1 g and μg conditions. A gap or stability region was observed in the specific V/ V o range under 1 g conditions. In the gap or stable region, after the gravity changed from 1 g to μg conditions, the temperature signals showed oscillation. From these results, the critical temperature difference under the μg conditions appeared to be smaller than that under the 1 g conditions. Temperature signals were defined as 6 different types of states. The various temperature oscillatory state regimes were obtained on a Δ T− V/ V o plane under 1 g and μg conditions. Under μg conditions, in these experimental conditions, all temperature oscillatory states exhibited only the Periodic state.