Shear-wave speeds and elastic moduli for different liquids. Part 2. Experiments

Abstract

In this paper we describe the experimental apparatus that we use to measure transit speeds. Tables of measured values of transit speeds and the corresponding values of the shear modulus are presented. The criteria we use to determine if a transit speed is a shear-wave speed are described and applied to the data. The main criteria are that transit speeds should be independent of the gap size and the corresponding value of the shear modulus should be consistent with independent rheometrical measurements. All the elastic liquids and many liquids that are usually assumed to be Newtonian satisfy our criteria for shear waves. We present evidence that the measured wave speeds are associated with slower-relaxing molecular structures in the liquids.