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

Abstract: 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 Oh. The viscosity ranges measured are about O(10^0) to O(104) mPas for shear viscosity and O(10^1) to O(10^3) mPas for apparent extensional viscosity. Our experimental results show that, at least for the range of Oh > 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.