Adam Witt

Predicting oxygen transfer efficiency at low-head gated sill structures

An improved model for predicting oxygen transfer efficiency at gated sills is presented. An analysis of field measurements from eight gated sill structures is used to develop a dimensionless relationship between inflow conditions, dam geometry and oxygen transfer efficiency. The oxygen transfer coefficient is estimated from scaled formulations of the liquid film coefficient, mean bubble diameter, air entrainment rate and turbulent energy dissipation rate. The model is validated with additional field measurements adjusted for temperature and effective saturation concentration. A design parameter for gated sill dams is introduced giving a relationship between gate opening and oxygen transfer efficiency. Improved prediction of oxygen transfer in the field is a tool that can be used to successfully operate gated structures to meet oxygen concentration requirements and to assist in the design of remediation technologies.

Development and Implementation of an Optimization Model for Hydropower and Total Dissolved Gas in the Mid-Columbia River System

AbstractManaging energy, water, and environmental priorities and constraints within a cascade hydropower system is a challenging multiobjective optimization effort that requires advanced modeling a...

The Economic Benefits of Multipurpose Reservoirs in the United States-Federal Hydropower Fleet

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Evaluation of the feasibility and viability of modular pumped storage hydro (m-PSH) in the United States

The viability of modular pumped storage hydro (m-PSH) is examined in detail through the conceptual design, cost scoping, and economic analysis of three case studies. Modular PSH refers to both the compactness of the project design and the proposed nature of product fabrication and performance. A modular project is assumed to consist of pre-fabricated standardized components and equipment, tested and assembled into modules before arrival on site. This technology strategy could enable m-PSH projects to deploy with less substantial civil construction and equipment component costs. The concept of m-PSH is technically feasible using currently available conventional pumping and turbine equipment, and may offer a path to reducing the project development cycle from inception to commissioning.

Predicting Total Dissolved Gas Travel Time in Hydropower Reservoirs

AbstractLarge spills at hydropower facilities can produce environmentally unfavorable supersaturated total dissolved gas (TDG) conditions. Enhanced coordination between adjacent hydropower faciliti...

Total dissolved gas prediction and optimization in RiverWare

................................................................................................................................................ ix 1. BACKGROUND AND INTRODUCTION ........................................................................................... 1 2. METHODOLOGY ................................................................................................................................. 4 2.1 TDG PREDICTION ..................................................................................................................... 5 2.2 DATA PROCESSING AND ASSUMPTIONS ........................................................................... 7 2.2.1 Data Collection and Preliminary Filtering ..................................................................... 7 2.2.2 Project Specific Data Filtering and Assumptions .......................................................... 9 2.3 CALIBRATION AND VALIDATION ....................................................................................... 9 2.4 RESULTS .................................................................................................................................. 11 2.5 RIVERWARE OPTIMIZATION .............................................................................................. 22 3. FUTURE WORK ................................................................................................................................. 24 4. CONCLUSION .................................................................................................................................... 25 5. REFERENCES ..................................................................................................................................... 26