Convection of a heat-generating fluid in a rotating cylindrical cavity subject to transverse vibrations

abstract The goal of this research is to study experimentally and theoretically the influence of transversal vibrations on the average convection of a non-isothermal fluid in a rotating cavity when the rotational frequency and vibration frequency approach each other. The research involves experimental studies of the convection of a heat-generating fluid in a rotating horizontal cylinder with isothermal boundaries subject to translational vibrations, perpendicular to the rotation axis. In the absence of vibrations, at fast cavity rotation the fluid is in an equilibrium state in the centrifugal force field with the temperature maximum at the cavity axis. The excitation of average convection and increase of heat transport is discovered when the vibration frequency is near to the rotation frequency. At some discrepancy between the frequencies, the resonance excitation of azimuthal two-dimensional inertial oscillations of the non-isothermal fluid column takes place. This results in significant decrease of the temperature at the cavity axis. When the frequencies coincide, the vibrations break the axial symmetry of the centrifugal force field. The resulting force field is stationary in the cavity frame and results in an intensive thermal convection; the theoretical analysis of this phenomenon is presented. The dependence of heat transport on the parameters of vibrations is determined both in the case of resonance liquid oscillations and in the case of equal frequencies. The vibrational and the centrifugal mechanisms play the key role in the convection. The transverse vibrations are demonstrated to be an efficient tool for the control of thermal convection in rotating systems.