Effect of viscosity on flow patterns of pumping-up of liquid generated by a cone rotating at the liquid surface has been experimentally studied with various concentrations of glycerol aqueous solution. We have previously found that the higher viscous non-Newtonian fluid was lifted-up along the conical surface with a radial filament-wise pattern, which is quite different from the monotonic thin film-wise pattern observed for the lower viscous fluid such as water. In order to elucidate the

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... -up mechanism, a transition diagram indicating the critical rotation rate is obtained as a function of viscosity of Newtonian fluid in this study, varying from the lower value of water (μ = 0.890 mPa·s) to the higher one of glycerin (μ = 910 mPa·s). It is found that there are three categories depending on the viscosity classified as 1) film-wise pumping-up region for the viscosity μ ≤ 134 mPa·s, 2) filament-wise pumping-up one for the viscosity μ ≥ 520 mPa·s, and 3) no pumping-up phenomenon occurs for 134 < μ < 520 mPa·s.