Pumping using thermal waves

Abstract

It is shown that thermal waves applied on the bounding surface of a horizontal slot generate a pumping effect. Reynolds stress developed by the change in the flow field due to the thermal inertia associated with the penetration of the wave into the fluid interior drives the net fluid movement in the horizontal direction. The induced flow rate increases with the wave speed, but excessive wave speed reduces it as convection becomes limited only in the near-wall area. The excessive increase of the wavelength and its excessive decrease reduce the flow rate. An increase in the wave amplitude increases the flow rate with a saturation limiting its growth. Judicious selection of the wave speed and wavelength of a thermal wave provides a means for optimizing the wave-induced pumping. The magnitude of the pumping increases with a reduction of Prandtl number.