On the formation of thermal drift

It has been recently shown [A. Abtahi and J. M. Floryan, "Natural convection and thermal drift," J. Fluid Mech. 826, 553 (2017)] that a horizontal flow, the thermal drift, can be created by applying spatially periodic heating to a corrugated plate. The presence of corrugations and its proper placement with respect to the heating pattern are essential. This analysis demonstrates that such drift can result from the interaction of the corrugated plate with any temperature field of the same spatial periodicity regardless of how this field is created. This principle is demonstrated through an analysis of convection in a horizontal slot with one plate heated and the opposite plate corrugated.