Abstract: | Large-scale motions developing against the background of developed convective turbulence in a rectangular vessel heated from below, in which a horizontal disk floats freely at a fixed depth, are studied experimentally. It is found that regular or chaotic oscillations may develop in the vessel. Transitional regimes characterized by interruptions of the motion or frequency variations are also possible. A regime map in the Rayleigh number — relative disk depth plane is constructed. It is shown that in the regular-oscillation regime the oscillation frequency is a linear function of the Rayleigh number. |