Turbulent gravity-stratified shear flows
- 1 January 1984
- journal article
- research article
- Published by Cambridge University Press (CUP) in Journal of Fluid Mechanics
- Vol. 138, 353-378
- https://doi.org/10.1017/s002211208400015x
Abstract
Two simple turbulent shear flows, namely a surface jet and a mixing layer, under the influence of stable gravity stratification, were investigated experimentally. The shear flows were generated in the laboratory by letting fresh water flow over saline water in a two-dimensional channel. Velocity and salinity measurements were made using a hot-film probe and a single-electrode conductivity probe. The experimental results for the two flows were correlated each using a different set of length and velocity scales. The initial development of the flows was relatively unaffected by the stable stratification. As the shear flows grew in thickness, they were observed to have a tendency to approach a ‘neutrally stable state’ in which the turbulent motion neither extracted energy from nor lost energy to the mean flow. The gradient Richardson number in this neutrally stable state was found to have the critical value predicted by linear inviscid stability theory. The decay of turbulent intensity in the longitudinal direction was observed to follow a power-law relationship similar to the one obtained by Comte-Bellot & Corrsin (1966) for the decay of grid-generated turbulence.Keywords
This publication has 15 references indexed in Scilit:
- The planar turbulent jetJournal of Fluid Mechanics, 1976
- Experiments on instability and turbulence in a stratified shear flowJournal of Fluid Mechanics, 1973
- Numerical studies of the stability of inviscid stratified shear flowsJournal of Fluid Mechanics, 1972
- A rapidly varied flow phenomenon in a two-layer flowJournal of Fluid Mechanics, 1971
- Stability of a Stratified Free Shear LayerPhysics of Fluids, 1971
- The use of a contraction to improve the isotropy of grid-generated turbulenceJournal of Fluid Mechanics, 1966
- Mixing of dense fluid in a turbulent pipe flow Part 1. Overall description of the flowJournal of Fluid Mechanics, 1960
- Turbulent entrainment in stratified flowsJournal of Fluid Mechanics, 1959
- Turbulent flow in a stably stratified atmosphereJournal of Fluid Mechanics, 1958
- Turbulent transport of heat and momentum from an infinite rough planeJournal of Fluid Mechanics, 1957