Vibrational convection of heat-generating fluid in a rotating horizontal cylinder. The role of relative cavity length

Thermal convection of fluid with internal heat sources in a rotating horizontal cylinder with isothermal boundary and adiabatic ends is investigated experimentally. Under the action of gravity nonisothermal liquid oscillates in the cavity frame. These tidal oscillations generate the average mass force and, as a result, excite convection. The steady convection developing by this mechanism is called thermal vibrational. Centrifugal force in the considered case plays a stabilizing role. The objects of studying are the excitation thresholds of the averaged convection, heat transfer and the structure of convective flows. The parameters varying in the experiments are heat release rate, relative length of the cylinder and rotation velocity. It is found that the inertial waves which are generated near the ends of the cavity by tidal oscillations of nonisothermal liquid effect the convection. The intensity of flows excited by these waves is relatively low, but significant especially below the threshold of thermal vibrational convection. It is shown that the influence of inertial waves on heat transfer and structure of convective flows strongly depends on the cavity aspect ratio.