Instabilities of thermocapillary-buoyant-Coriolis flow of medium Prandtl fluid in a slowly rotating annular pool

Abstract

In differently heated slowly rotating annular pools, the thermocapillary force, buoyancy force, and Coriolis force drive fluid flows and induce various flow instabilities. To understand these complex flow instabilities, the linear stability of axisymmetric thermocapillary-buoyant-Coriolis flow was investigated for medium Prandtl number fluid in an annular pool slowly rotating in a counter-clockwise direction. The neutral states for the incipience of instabilities were determined by a linear stability analysis, and the underlying mechanisms were clarified using energy budgets. Three types of flow instabilities were identified for Taylor numbers ranging from 0 to 60. The results showed that the sign of the temperature perturbation in the bulk and that on the surface right above it governed the mechanisms of the stationary and oscillatory instabilities. This work can be helpful for understanding the combined effects of thermocapillary force, buoyancy force, and Coriolis force on flow instabilities.