Thermo-Oscillatory Convection

Average thermal convection of an incompressible fluid performing high-frequency oscillations in a straight channel at rest is considered. It is shown that the Stokes layers play an important role in the excitation of average flows, in addition to the classical thermovibrational mechanism. Skin-layer flow generation is identified as a mechanism additional to the thermovibrational mechanism whose contribution is determined by the relative oscillation amplitude: it can have both a destabilizing and a stabilizing effect, depending on the amplitude.