Viscoelastic flow behavior in accelerating shear fields
Abstract
Two techniques for measuring dynamic viscoelastic behavior were investigated: the cone-and-plate and the concentric cylinder Couette rheometers, both with accelerating rotating members. It is analytically shown and experimentally confirmed that the error introduced by inertia resulting from angular acceleration in the cone-and-plate rheometer can be reduced to any desirable level by reduction of the cone angle for any finite acceleration. The optical cylindrical Couette rheometer is shown to be capable of enabling direct observation of velocity in dynamic shear fields with large inertial effects. The two devices complement each other in that the cone-and-plate system can be used to characterize the dynamic fluid properties, and the optical Couette device can be used to examine inertial effects. Simulations of accelerating Couette flow were conducted for the Newtonian, Prandtl-Eyring, Maxwell, Metzner-White, and Oldroyd models.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- December 1975
- Bibcode:
- 1975PhDT........57L
- Keywords:
-
- Couette Flow;
- Flow Characteristics;
- S Waves;
- Viscoelasticity;
- Newtonian Fluids;
- Relaxation Time;
- Rheometers;
- Traveling Waves;
- Velocity Distribution;
- Fluid Mechanics and Heat Transfer