Computational Fluid Dynamics Modeling of The Dalles Project: Effects of Spill Flow Distribution Between the Washington Shore and the Tailrace Spillwall

PDF Version Also Available for Download.

Description

The U.S. Army Corps of Engineers-Portland District (CENWP) has ongoing work to improve the survival of juvenile salmonids (smolt) migrating past The Dalles Dam. As part of that effort, a spillwall was constructed to improve juvenile egress through the tailrace downstream of the stilling basin. The spillwall was designed to improve smolt survival by decreasing smolt retention time in the spillway tailrace and the exposure to predators on the spillway shelf. The spillwall guides spillway flows, and hence smolt, more quickly into the thalweg. In this study, an existing computational fluid dynamics (CFD) model was modified and used to characterize ... continued below

Physical Description

PDFN

Creation Information

Rakowski, Cynthia L.; Serkowski, John A. & Richmond, Marshall C. December 1, 2010.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

The U.S. Army Corps of Engineers-Portland District (CENWP) has ongoing work to improve the survival of juvenile salmonids (smolt) migrating past The Dalles Dam. As part of that effort, a spillwall was constructed to improve juvenile egress through the tailrace downstream of the stilling basin. The spillwall was designed to improve smolt survival by decreasing smolt retention time in the spillway tailrace and the exposure to predators on the spillway shelf. The spillwall guides spillway flows, and hence smolt, more quickly into the thalweg. In this study, an existing computational fluid dynamics (CFD) model was modified and used to characterize tailrace hydraulics between the new spillwall and the Washington shore for six different total river flows. The effect of spillway flow distribution was simulated for three spill patterns at the lowest total river flow. The commercial CFD solver, STAR-CD version 4.1, was used to solve the unsteady Reynolds-averaged Navier-Stokes equations together with the k-epsilon turbulence model. Free surface motion was simulated using the volume-of-fluid (VOF) technique. The model results were used in two ways. First, results graphics were provided to CENWP and regional fisheries agency representatives for use and comparison to the same flow conditions at a reduced-scale physical model. The CFD results were very similar in flow pattern to that produced by the reduced-scale physical model but these graphics provided a quantitative view of velocity distribution. During the physical model work, an additional spill pattern was tested. Subsequently, that spill pattern was also simulated in the numerical model. The CFD streamlines showed that the hydraulic conditions were likely to be beneficial to fish egress at the higher total river flows (120 kcfs and greater, uniform flow distribution). At the lowest flow case, 90 kcfs, it was necessary to use a non-uniform distribution. Of the three distributions tested, splitting the flow evenly between Bay 7 and Bay 8 had hydraulics deemed most beneficial for egress by CENWP fisheries biologists and regional fishery agency representatives. The numerical and physical model results were very similar, building confidence in both hydraulic tools.

Physical Description

PDFN

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: PNNL-20064
  • Grant Number: AC05-76RL01830
  • DOI: 10.2172/1007371 | External Link
  • Office of Scientific & Technical Information Report Number: 1007371
  • Archival Resource Key: ark:/67531/metadc831582

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • December 1, 2010

Added to The UNT Digital Library

  • May 19, 2016, 3:16 p.m.

Description Last Updated

  • Nov. 23, 2016, 11:15 a.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 2

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Rakowski, Cynthia L.; Serkowski, John A. & Richmond, Marshall C. Computational Fluid Dynamics Modeling of The Dalles Project: Effects of Spill Flow Distribution Between the Washington Shore and the Tailrace Spillwall, report, December 1, 2010; Richland, Washington. (digital.library.unt.edu/ark:/67531/metadc831582/: accessed July 18, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.