A Coaxial-Cylinder Elastoviscometer

Oscillatory pipe flow: A comparison between predicted and observed displacement profiles

“…To solve the equation of motion (13), a suitable relation between stress and strain rate must be postulated together the appropriate boundary conditions which are V--0 on r = R. A general rheological equation of state is taken in the form-~+(r) = 7+(r),/7 exp -iO(r), [19] where /7 = mod #+ [20] /x + = ,u'-iß" [21] and/x + is the complex viscosity. 9 + is the shear rate.…”

“…The work of Oldroyd, Strawbridge and Tores (19) exemplifies this approach. However, oscillatory pipe flow offers an alternative means of examining fluid response under large strain amplitudes.…”

Developing laminar flows with visco-elastic and non-Newtonian liquids

“…Various results have been used to assess the merits of different constitutive equations i. e. those equations relating the stress to the rate of strain in the media (3,4,5). They are formulated to contain one or more time constants to describe the time dependent properties of viscoelastic fluids.…”

Flow of elastico-viscous liquids in channels under the influence of a periodic pressure gradient, part 1

“…J [9] In the case of periodic motion, it is observed that there is a solution in which both W and P~:+) vary sinusoidMly, but because G(r, t) varies with the square of the velocity gradient the normal stresses (P~+~) in A' and Pi~z) in B') have associated with them steady components as well as periodic components with frequency twice that of W.…”