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

摘要

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, whi style="font-family:Verdana;">c style="font-family:Verdana;">h 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 style="font-family:Verdana;">? style="font-family:Verdana;">of Newtonian fluid in this study, varying from the lower value of water ( style="line-height:11.64px;font-family:Verdana;">μ style="line-height:11.64px;font-family:Verdana;">? style="font-family:Verdana;">= style="font-family:Verdana;">? style="font-family:Verdana;">0.890 mPa·s) to the higher one of glycerin ( style="line-height:11.64px;font-family:Verdana;">μ style="line-height:11.64px;font-family:Verdana;">? style="font-family:Verdana;">= 910 style="font-family:Verdana;">? style="font-family:Verdana;">mPa·s). It is found that there are three categories depending on the viscosity classified as? style="font-family:Verdana;">1 style="font-family:Verdana;">) film-wise pumping-up region for the viscosity style="font-family:Verdana;">? style="line-height:11.64px;font-family:Verdana;">μ style="line-height:11.64px;font-family:Verdana;">? style="font-family:Verdana;">≤ style="font-family:Verdana;">? style="font-family:Verdana;">134 style="font-family:Verdana;">? style="font-family:""> style="font-family:Verdana;">mPaname="OLE_LINK5">name="OLE_LINK3"> style="font-family:Verdana;">·s, style="font-family:Verdana;">?2 style="font-family:Verdana;">) filament-wise pumping-up one for the viscosity style="font-family:Verdana;">? style="line-height:11.64px;font-family:Verdana;">μ style="line-height:11.64px;font-family:Verdana;">? style="font-family:Verdana;">≥ style="font-family:Verdana;">? style="font-family:Verdana;">520 style="font-family:Verdana;">? style="font-family:Verdana;">mPa·s, and? style="font-family:Verdana;">3 style="font-family:Verdana;">) no pumping-up phenomenon occurs style="font-family:Verdana;">? style="font-family:Verdana;">for 134? style="font-family:Verdana;">/span> style="font-family:Verdana;">? style="line-height:11.64px;font-family:Verdana;">μ style="line-height:11.64px;font-family:Verdana;">? style="font-family:Verdana;">< 520 style="font-family:Verdana;">? style="font-family:Verdana;">mPa·s.