Properties of Steady, Viscosity-Stratified Flow to a Line Sink.
Abstract
Viscosity stratification (variation of the viscosity of a fluid with depth) can significantly modify the velocity profiles observed in a fluid being selectively withdrawn from a tank or duct. A mathematical model is developed to predict velocity distribution for steady, Newtonian, slow, laminar, two-dimensional, viscosity-stratified flow to a line sink. The mathematical model was verified in experiments conducted in three flumes using sugar and carboxymethylcellulose to create density and viscosity gradients. Viscosity stratification caused the velocity profile to become skewed in the direction of lower viscosity. Criteria are presented to determine when velocity profiles are skewed. Existence of skewness depends on three dimensionless parameters: dimensionless viscosity graident (A or C); ratio of buoyancy to viscous forces (B); and dimensionless distance from sink (X). The results of the verified model are extended to (a) viscosity-stratified flow over a weir, and (b) flow of a Bingham plastic in which yield stress varies with depth. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1979
- Accession Number
- ADA073371
Entities
People
- Thomas M. Walski