Persistent link for this collection

Search within Reports


Recent Submissions

Now showing 1 - 3 of 3
  • Item
    StreamLab06: Overview of Experiments, Instrumentation, and Data collection
    (St. Anthony Falls Laboratory, 2010-11) Marr, Jeff; Wilcock, Peter; Hondzo, Miki; Foufoula-Georgiou, Efi; Johnson, Sarah; Hill, Craig; Leonardson, Rebecca; Nelson, Peter; Venditti, Jeremy; O'Connor, Ben; Ellis, Christopher R.; Mullin, James; Jefferson, Anne; Clark, Jeff
    This report summarizes the StreamLab06 experimental research program conducted in the St. Anthony Falls Laboratory (SAFL) Main Channel facility from April through October 2006. The experiments were funded through the National Center for Earth-surface Dynamics and involved a host of researchers, graduate students, visitors, and undergraduate students. The experiments were organized into seven phases of work. The first two phases of the project involved testing of conventional and surrogate bedload monitoring technologies (Marr et. al. 2007). The last five phases involved interdisciplinary research of sediment transport and ecohydraulics. This report focuses on the later phases of the project and does not include the bedload monitoring technologies. This report contains information on the organization of the experiments, the methodologies and protocols used to collect data, the types of data collected, data structure and format, and information on data storage and access.
  • Item
    Index Test of Unit #1 Prospect Powerhouse #2
    (St. Anthony Falls Laboratory, 1987-11) Voigt, Richard L.
    An index test was performed September 30 and October 1, 1987, on Unit #1 of Prospect Powerhouse #2, located near the town of Prospect, Oregon. The testing was requested by the American Hydro Corporation and was scheduled to be in conjunction with a possible runner upgrade of the facility. The facility owner is Pacific Power of Portland, Oregon. The primary personnel involved were: Mr. W. Colwill, of American Hydro Corporation; Messr's T. O'Conner and R. Landolt of Pacific Power; Mr. R. Voigt, Jr., of St. Anthony Falls Hydraulic Laboratory, University of Minnesota. Numerous Pac.1f1c Power maintenance and operational personnel were also involved. The purpose of an index tes,t is to determine the relative unit efficiency at various wicket gate positions. Through this type of testing the most efficient wicket gate position can be verified. This is typically determined by varying the wicket gate position from either full gate to closed gate or vice versa, in a series of small, usually 5 to 10%, increments. At each position, approximately 15 to 20 parameters are measured. Some of these parameters such as generator output and·relative flow measurement are used in the computation of the relative efficiency values, while others may affect turbine efficiency either directly or indirectly.
  • Item
    Physical Model Study of the Fairfax Water Off-Shore Intake: New Modifications and the Study of the Flow Patterns around the Sand Barrier
    (St. Anthony Falls Laboratory, 2008-09) Mohseni, Omid; Howard, Adam; Lueker, Matthew
    To withdraw better water quality from the Potomac River for a water treatment plant during flow conditions under 20,000 cfs, Fairfax Water in VA had an off-shore river intake built in 2004. The intake was comprised of a 36-ft diameter hexagon concrete structure sitting on the bed of the river with a sand barrier around it to minimize the sand withdrawal. The sand barrier is a nonagon concrete structure with approximately a 54 ft diameter. Since the intake started operating in late 2004, it has exhibited a significant amount of sand withdrawal. In 2007, a 1:10 scale model of the intake was built at the St. Anthony Falls Laboratory (SAFL) to study the causes of sand withdrawal, to modify the structure and to minimize the amount of sand withdrawal. The modifications conducted on the sand barrier resulted in a new geometry for the sand barrier, which was comprised of two wingwalls at the downstream end, a nose wall at the upstream end and a crown over the entire structure. The results of the tests conducted on this geometry showed that by building the new geometry for the sand barrier, the prototype bedload withdrawal should decrease by more than 60%. To further reduce the sediment withdrawal, a new study was required which is the subject of the current report. In this study, three more modifications were made to the sand barrier and tested. A total of 11 tests were conducted on the new geometries and the original geometry. In addition, the flow patterns around the original geometry of the sand barrier as well as the modified geometry were studied to determine if any further modification could decrease the bedload withdrawal. By studying the flow patterns and turbulence intensities around the structure, the final geometry was designed to include the crown, wingwalls and nose wall of the sixth geometry with a screen mounted on the half height of the walls around the structure. The screen was designed to prevent the eddies from dispersing the resuspended sediments in the water column along the height of the wall. The results of the tests conducted on this geometry suggest that the prototype bedload withdrawal should decrease by approximately 70%.