Experiment on multimode feedback control of non-linear thermocapillary convection in a half-zone liquid bridge

Feedback control on was carried out on non-linear thermocapillary convections in a half-zone liquid bridge of a high Prandtl number fluid. In the liquid bridge, the convection changes from a two-dimensional steady flow to a three-dimensional oscillatory one at a critical temperature difference. Feedback control was realized by locally modifying the free surface temperature using local temperature measured at different positions. The present study aims to develop a new control scheme by taking spatio-temporal azimuthal distribution of temperature fluctuation into account. The new control scheme achieved significant attenuation of the temperature oscillation compared with the previous one in a high Marangoni number range.