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.

Extended thermodynamics of a non-Newtonian fluid

“…We believe that our interpretation is the correct one. Support for our conviction comes from the fact that the pulse speed which we calculate in (6.20) from normal-stress differences and viscosity is of the same order of magnitude as the pulse speeds measured by Joseph et al as reported in~ [11].…”

“…We also describe the new proposition by Joseph et al [11] who have measured the speed of shear pulses and related it to their constitutive relation.…”

Climbing constant, second-order correction of Trouton's viscosity, wave speed and delayed die swell for M1

“…The apparatus and the measuring technique are described in Joseph et al [20] and in detail in Riccius [21].…”

Turbulent Boundary-Layer Drag Reduction

“…He forther conjectured that the net effect was equivalent to an increase in effective viscosity and a kinetic energy damping, with an attendant reduction in velocity fluctuations and near-wall Reynolds stress. The latter conjecture is not borne out by experiment (e.g., Virk 1975), Related models are reviewed by Toonder and Nieuwstadt (1999), who also discuss an idea by Joseph et al (1986) and Joseph (1990), who argued for viscoelastic behavior and "shear waves", and conducted some experiments to look for them, Toonder and Nieuwstadt conclude that this idea ",.. is only vaguely formulated and has not been experimentally tested or theoretically elaborated,"…”