Effect of centrifugal forces on the instability of the thermocapillary flow in partially confined half-zones

The stability of the axisymmetric steady thermocapillary flow in a cylindrical half-zone liquid bridge is investigated numerically for the case when the free surface is partially confined by a thin solid layer. A linear-stability and an energy analysis are performed to elucidate the dependence of the instability mechanism on the free-surface fraction which is defined as the length of the free part of the cylindrical surface relative to the full height of the zone. It is found that the balance of the elliptic instability and the centrifugal instability changes significantly, leading to three different types of instability depending on the free-surface fraction.