Fluctuations of Thermal-Solutal Capillary Convection at Different Mat Numbers under Microgravity

In this study, the effect of thermal Marangoni (Ma T ) number on the thermal-solutal capillary convection in a liquid bridge of n-decane/n-hexane solution under microgravity has been studied numerically. The Navier–Stokes equations coupled with the concentration diffusion equation are solved using the finite volume method. Unlike existing studies, the Soret effect is considered as well in the present work and a variety of new oscillation structures have been found. Present results indicate the concentration near the lower disk is always higher than that near the upper disk due to the Soret effect. The thermal-solutal capillary convective wave appears when the Ma T numbers is high. The wave includes standing wave and traveling wave, and the traveling wave appears first and then the standing wave is formed. The Ma T number affects the flow field structure in the oscillating state of thermal-solutal capillary convection in the liquid bridge. As the Ma T number increases, the wave number of thermal-solutal capillary convection changes from 4 to 5.