Combined effect of volume and gravity on the three-dimensional flow instability in noncylindrical floating zones heated by an equatorial ring

Abstract

The present paper strongly extends a previous analysis dealing with the investigation of the three-dimensional Marangoni flow instability in cylindrical floating zones (straight liquid column of full-zone extent) of a low Prandtl liquid laterally heated by a ring positioned around the equatorial plane and under microgravity conditions. The new study gives insights into the combined influence of volume and gravitational effects. The deformation of the free melt–gas interface due to the gravity field is taken into account. Parallel supercalculus is used to reduce the otherwise prohibitive computational time. The prominent features of the three-dimensional field are largely dependent on geometrical parameters. The results (full zone) are heretofore unseen and show that the interplay between the upper half and lower half of the liquid domain is an essential factor for the correct description of the phenomena under investigation. They are contrasted with the case of the half zone for which a rich variety of interesting and worthy contributions is available in literature.