Oscillatory Experiments with a Cone-and-plate Viscometer

Abstract

IN recent years the cone-and-plate viscometer has been used with some success in the measurement of second-order effects in elastico-viscous liquids. The relevant experiments are usually performed with a very small gap between the cone and plate and at speeds low enough for inertia effects to be ignored. Under these conditions it can be shown, theoretically, that when the motion of the liquid is caused by the relative axial rotation of the cone and plate, the resulting flow is of a simple-shearing type with no secondary flow, the rate of shear throughout the liquid being constant. The cone-and-plate viscometer is, therefore, a convenient instrument for investigating the behaviour of elastico-viscous liquids in a simple shearing flow.