Buoyant jet entrainment in stratified fluids
Abstract
The characteristic behavior of a turbulent round buoyant jet discharging into a linearly density-stratified stagnant ambient fluid is studied. Tracer concentrations profiles within the jet at several axial locations are measured experimentally by fluid sampling and fluorometric analysis. The terminal height of rise is measured visually and the dimensions of the subsequent spreading layer are determined from a vertical concentration profile measured in the layer. The integral equations with the available entrainment functions and a new density profile definition yield reasonable predictions of the jet behavior all the way to the height of rise. From the laboratory observations, significant entrainment flow is detected near the rise height and the jet mixing with ambient fluid in the region occupied by the spreading layer is not markedly inhibited. Therefore, past models that consider detrainment of jet fluid near the rise height or suggest that dilution computations should be corrected for the presence of the layer, are repudiated. Finally, the entrainment in the lower reaches of the jet trajectory is not markedly affected by the ambient density gradient.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1984
- Bibcode:
- 1984PhDT........27W
- Keywords:
-
- Buoyancy;
- Entrainment;
- Fluid Dynamics;
- Fluid Jets;
- Jet Boundaries;
- Jet Mixing Flow;
- Stratification;
- Turbulent Jets;
- Height;
- Integral Equations;
- Models;
- Predictions;
- Fluid Mechanics and Heat Transfer