Academic staff: Dr P.A. Mackinnon & Dr G.A. Hamill

Schematic diagram of a marine outfall with saline intrusion

Introduction

• Marine outfalls are used to discharge wastewater
• The diffuser section increases dilution
• Saline intrusion occurs when there is insufficient head to purge the seawater from the outfall
• Continuous saline intrusion may then occur by entrainment
• Saline intrusion can be exacerbated by wave action
• The consequence of intrusion is reduced efficiency

The Hydraulics Research Group is investigating saline intrusion in marine outfalls using numerical and physical modelling techniques

• This is a typical density profile generated by the model

• The numerical model uses the Computational Fluid Dynamics (CFD) package FLUENT to simulate the outfall flow

• Current investigations are incorporating the effects of wave action within the numerical model

• Experimental testing is carried out in the laboratory to provide data for validation of the numerical model

Above: Saline intrusion (shown in red) in a section of model outfall and the overall physical model

 

For more information contact: Dr. Naomi Shannon

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References

"Modelling of Saline Intrusion in a Long Sea Outfall."
N.R. Shannon, P.A. Mackinnon & G.A. Hamill
7th International Conference on Hydraulics Engineering Software - "HydroSoft '98"
Como, Italy, September 1998.
ISBN 1-85312-599-7 pp. 531-541

"An Experimental Investigation of Saline Intrusion in a Long Sea Outfall."
P.A. Mackinnon, N.R. Shannon, G.A. Hamill & B.M. Doyle
3rd International Conference on Advances in Fluid Mechanics
Montreal, Canada, May 2000.
ISBN 1-85312-813-9 pp. 33-42

"Evaluation of a Two-Dimensional Model of Saline Intrusion in an Outfall with Two Risers."
P.A. Mackinnon, N.R. Shannon & G.A. Hamill
4th International Conference on Hydromechanics - ICHD2000
Yokohama, Japan, September 2000.
ISBN 4-9980932-1-5 Volume II, pp. 753-758

"'Development and Evaluation of a Numerical Model to Simulate Wave Induced Flow Patterns in a Long Sea Outfall."
B.M. Doyle, P.A. Mackinnon, G.A. Hamill & N.R. Shannon
4th International Conference on Hydromechanics - ICHD2000
Yokohama, Japan, September 2000.
ISBN 4-9980932-0-7 Volume I, pp. 355-360

"Modelling of Saline Intrusion in a Long Sea Outfall with Two Risers."
N.R. Shannon, P.A. Mackinnon & G.A. Hamill
1st International Conference on Computational Methods in Multiphase Flow.
Orlando, USA, March 2001.
ISBN 1-85312-862-7 pp. 299-308

"Collection of data to validate a numerical model of wave induced intrusion in a marine outfall."
N.R. Shannon, P.A. Mackinnon , G.A. Hamill & B.M. Doyle
4th International Conferenec on Advances in Fluid Mechanics - AFM2002
Ghent, Belgium, May 2002.