Experimental modelling of Czochralski melt flow with a slow crystal dummy rotation

This study examines the efiect of slow crystal dummy rotation on three-dimensional oscillatory instability and time-dependent supercritical flow states in a Czochralski melt flow experimental model. To enable further comparison with numerical modelling, the experiments are carried out using a 20 cSt silicone oil as an experimental liquid and in a large diameter crucible, which allows one to work in a narrow temperature interval, so that temperature dependence of all the thermophysical properties of the experimental liquid can be neglected. The measurements confirm, partially qualitatively and partially quantitatively, earlier numerical predictions on destabilization ofthe Czochralski convective flow by a slow rotation. A simple power dependence of flow oscillations frequency on the Grashof and rotational Reynolds numbers that fits all the experimental runs was found.