Effect of Viscosity on Pumping-Up of Newtonian Fluid Driven by a Rotating Cone

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 pumping-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