Efficiency and Cavitation Effects of Hydroturbine Venting
Volkart and Bohac et al. have summarized much of the past work on aeration of hydroturbine releases to improve downstream water quality. Conventional alternatives for increasing dissolved...
Reviewing the Operating Objectives of the TVA Reservoir System
Under the Tennessee Valley Authority's Lake Improvement Plan, approved by the Board of Directors in February 1991, minimum flows will be provided systemwide, the releases...
From Mean Fluxes to a Detailed Experimental Investigation of the Gas Transfer Process
Three new experimental techniques are discussed which allow a much more detailed investigation of the gas transfer process than any previous techniques. Using heat as a proxy tracer for...
Measurement of Reaeration Coefficient with the Soluble Solids Probe
The results of analytical and experimental studies are presented, showing that the proposed method for indirect determination of gas transfer coefficients at gas-liquid interfaces, based...
Dissolved Oxygen and Woody Debris: Detecting Sensitive Forest Streams
Early watershed studies showed that timber harvesting and yarding could depress dissolved oxygen in nearby streams when fresh slash entered streams and streamside shade was reduced. State...
Technology Development for Auto-Venting Turbines
Experimentation with venting air into the hydroturbines at Norris Dam has convinced the Tennessee Valley Authority (TVA) that this is a viable method for increasing dissolved oxygen (DO)...
A Simple Empirical Model of Aeration at Navigation Dams
In a study of aeration at 28 dams in the upper Ohio River basin, site-specific least-squares linear regression models were used to describe the dissolved oxygen deficit below each dam...
Oxygen Transfer at Spillways
A relationship for oxygen transfer efficiency, E, at spillways and gated spillways with a hydraulic jump or plunge pool, has been developed from conceptual considerations and fit to measurements...
Sidestream Elevated Pool Aeration Station Design
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) is constructing a system of five Sidestream Elevated Pool Aeration (SEPA) stations along the 35.8 mile Calumet River,...
Mechanical Aeration System Design for Reservoir Tailwater Enhancement
Low dissolved oxygen (DO) concentrations in tailraces below hydropower facilities has been identified as a problem at some projects during nongeneration periods. One technique which may...
Experiment on the Efficiency of an Aspirator-Blower Type Aerator
An aspirator-blower type aerator was designed and tested successfully for small lake application. The experiment showed that significant amount of air flow can be generated by the aspirator...
Water Surface Flow and Exchange Induced by a Bubble Plume
Aeration is a common method to increase dissolved oxygen in the water of stratified (or non-stratified) lakes. In this method compressed air is injected at some depth, and gas is transferred...
The Effect of Surface Films on Concentration Fluctuations Close to a Gas/Liquid Interface
Modeling of gas/liquid mass transport requires knowledge concerning the behavior of near-surface concentration fluctuations at clean and film-covered gas/liquid interfaces. Previous measurements...
Barometric Pumping of Contaminated Gases Through Fractured Permeable Media
Contaminated gases may be transported vertically through a fractured permeable medium by the breathing process which is associated with cyclical changes in the barometric pressure. A review...
Experimental Difficulties Encountered in Testing Air/Water Mixtures
The Tennessee Valley Authority and Voith Hydro, Inc., are conducting a joint research project to study the effects of air admission on hydraulic turbines. Francis turbine models, homologous...
The Role of Computational Fluid Dynamics in Hydroturbine Analysis
Prospects of developing comprehensive methods of computational fluid dynamics for the analysis and design of new generation of hydroturbines are considered. Unique requirements for this...
A Gas-Flow Source Term from a Nuclear Waste Container in an Unsaturated Medium
The potential nuclear waste repository at Yucca Mountain is to be in partially saturated rock. Released radioactive gases would have a direct pathway to the biosphere. The entry of air...
Minimizing the Risk of Unsuccessful Modeling Exercises
Monte Carlo simulation techniques were employed to relate input parameter uncertainties to the characteristics of model output accuracy and reliability, and to the probability of successfully...
Reservoir Reevaluation in TVA
Demands for the use of dams and reservoirs tend to change after the projects are completed. The Tennessee Valley Authority (TVA) works with State and local groups to try to increase the...
Advection-Diffusion Calibration of Dissolved Oxygen
Modifications of J.J. Leendertse's water-quality model for improving calculations of dissolved oxygen concentrations in Jamaica Bay, New York, are discussed. Changes to the...
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