Experimental study of cold plume instability in large Prandtl number Czochralski melt: Parametric dependences and scaling laws

•Study of cold plume instability in large-Prandtl-number Czochralski melt flows.•Measurements by two independent and fully non-intrusive experimental techniques.•Measured critical parameters are reported in form of semi-empirical relations.

A parametric experimental study of the cold plume instability that appears in the large-Prandtl-number Czochralski melt flows is reported. The critical temperature difference (the critical Grashof number) and the frequency of appearing oscillations were measured for varying Prandtl numbers, aspect ratios of the melt, and crystal/crucible radii ratio. The measurements were carried out by two independent and fully non-intrusive experimental techniques. The results are reported as dimensional and dimensionless parametric dependences, and then are joined into relatively simple empirical relations showing how the critical Grashof number and the frequency of emerging oscillations depend on other parameters.