Oxygen Transfer Similitude for a Vented Hydroturbine
design, dissolved oxygen, hydroelectric, impoundments, models, prototype, spillway, turbines, water quality
Misc. Report W-94-1
National Technical Information Service
Discharge from large impoundments of water, such as those found behind hydroelectric installations, can have major impacts on downstream water quality. Discharges from surface layers over spillways can significantly improve dissolved oxygen (DO) levels in tailwaters. Conversely, discharges from lower hypolimnetic regions in a reservoir can release anoxic waters whose low DO can result in large-scale environmental damage. A new technology has been developed called the autoventing turbine that aspirates air into hydroelectric turbine discharges in order to substantially improve release DO when it is needed. There is a great deal of research involved in determining the limits of effectiveness of oxygen transfer through autoventing turbines, and improving the performance of early prototypes. Many preliminary investigations at several different locations failed to reveal a single best design for the autoventing turbine. As a result current research efforts have gone toward designing and testing of turbine models and evaluation of the effectiveness of model runner configurations.