An experimental study of oscillatory convection in liquid gallium

Abstract

Results are presented of an experimental study of the onset of time-dependent flows in a sample of liquid gallium subjected to a horizontal temperature gradient. The primary control parameter is the Grashof number which is set by the temperature difference. However, we have also taken the novel approach of varying the Prandtl number in a systematic way using the applied mean temperature. This has uncovered some surprising new dynamical states. Furthermore, the interaction between competing oscillatory flows has produced interesting dynamical behaviour including secondary Hopf bifurcations where both the frequency and amplitude grow from zero as the critical point is passed.