Effect of rotation on thermal convection in horizontal plane layer subject to circular vibration

Abstract

The stability of quasi-equilibrium of a horizontal liquid plane layer with isothermal boundaries of different temperatures, subject to circular vibrations in the horizontal plane, is experimentally studied. The rotation of the cavity around the vertical axis is set independently. In order to exclude from consideration the destabilizing effect of the gravity field, the layer is heated from the top. In the absence of rotation, the circular vibrations lead to the threshold excitation of vibrational thermal convection in the layer of nonisothermal liquid, in spite of its stable stratified in the gravity field. At given vibration amplitude and temperature difference at the layer boundaries, the threshold is determined by sharp increase in heat transfer with a monotonic increase in the vibration frequency. The size of the convective spatial structures is determined by the layer thickness. In the case of high-frequency vibrations, convection is determined by dimensionless parameters: gravitational Rayleigh number Ra and vibrational parameter R v. The thresholds of vibrational convection excitation on the plane of these parameters in the case of circular vibrations coincide with the theoretically predicted stability boundary for linear vibrations. It is shown that rotation has a stabilizing effect on vibroconvective stability, similar to the case of gravitational convection. The threshold value of the vibration parameter R v grows with an increase in the dimensionless rotation velocity ω rot. Under conditions of the performed experiment, the structure of convective cells and the wave number of structures in the supercritical region do not change in comparison with ω rot = 0.