Thermal convective instabilities in cylindrical enclosures and floating liquid columns under normal and microgravity conditions

The analysis deals with a comparative study of available theoretical and numerical results about the dynamics of natural (gravitational), Marangoni and related mixed convection in various axisymmetrical geometrical configurations. Emphasis is given to fundamental knowledge provided over the last years by landmark analyses as well as to very recent novel contributions. Attention is focused on the cases of cylindrical enclosures and floating zones under different possible heating conditions (lateral heating and heating from below). The differences between gravitational and Marangoni convection are stressed and cross-comparison is used as an useful means to shed additional light on the fundamental nature and structure of both these types of convection in these axisymmetric geometrical models. Silicon melt is considered as a reference case owing to the widespread use of this liquid in various technological processes pertaining to the growth of single-crystalline specimens from initial polycrystalline samples.