Experimental study on the relationship between extensional and shear rheology of low-viscosity power-law fluids

This paper investigates the relationship between extensional and shear viscosity of low-viscosity power-law fluids. We show the first experimental evidence of the conditions satisfying the same power exponents for extensional and shear viscosity, as indicated by the Carreau model. The extensional and shear viscosity are respectively measured by capillary breakup extensional rheometry dripping-onto-substrate (CaBER-DoS) and by a shear rheometer for various Ohnesorge number O h . The viscosity ranges measured are about O ( 1 0 0 ) to O ( 1 0 4 ) mPa ⋅ s for shear viscosity and O ( 1 0 1 ) to O ( 1 0 3 ) mPa ⋅ s for apparent extensional viscosity. Our experimental results show that, at least for the range of O h > 1 , the power-law expression for the liquid filament radius, apparent extensional viscosity, and shear viscosity holds, even for low-viscosity fluids under our experimental conditions. • Low-viscosity power-law fluids was experimentally examined. • Extensional and shear viscosity are measured for a wide range. • The first experimental evidence supporting the theoretical prediction was obtained. • The power exponents of extensional and shear viscosity are the same at least O h > 1. • Our findings are useful for predicting extensional viscosity from shear viscosity.