Onset of zero Prandtl number convection

(Received 12 November 1991, accepted in final form 17 Febraury 1992)

Abstract
The transition to convection in a zero Prandtl number fluid with stress-free and perfectly conducting boundaries differs significantly from finite Prandtl number convection, giving rise to a three-dimensional pattern. Two possible scenarios are described and compared with recent numerical simulations by Thual [1].