Drift of a Free-floating Body in a Convective Layer Heated by Radiation

The one-dimensional dynamics of a disk floating freely at a fixed depth in a layer of liquid under conditions of natural convection caused by radiation heating was studied experimentally. It was shown that the dynamics of the disk depends on its optical properties. A disk with a light-reflecting surface demonstrated quasi-periodic motions along the cell. The period of oscillations depends on both the length of the cell and the immersion depth of the disk. The light-absorbing or transparent disk is pressed against the side wall after brief wanderings and remains there until the end of the experiment.