1. ERDC Knowledge Core
2. Pre - Engineer Research and Development Center (ERDC)
3. Hydraulics Laboratory - (8/1/1972 - 9/1996)
4. Publication
5. Miscellaneous Paper

Title:	St. Stephen Powerhouse tailrace velocity measurement
Authors:	United States. Army. Corps of Engineers. Charleston District. Fagerburg, Timothy L.
Keywords:	Hydraulic structures Power plants Hydroelectric power plants St. Stephen Powerplant St. Stephen Powerhouse South Carolina Tailraces Velocity measurement Flow velocity
Publisher:	Hydraulics Laboratory (U.S.) Engineer Research and Development Center (U.S.)
Series/Report no.:	Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; HL-86-6.
Description:	Miscellaneous Paper Abstract: Tests were conducted to provide a prototype evaluation of the operating conditions of the project and to evaluate the adequacy of the repairs and remedial work performed in the channel downstream of the tailrace. Prototype measurements were made to define the relative magnitudes of velocities and the surface flow patterns in the channel downstream of the tailrace and the displacement, if any, of the stone protection material resulting from various turbine operations and tailwater conditions. Results of the data collection included determination of (A.) velocity distributions at various ranges across the channel; (B.) velocity profiles at the toe of the slope and at the observed location of highest velocity; and (C.) unusual surface flow patterns that are produced by different combinations of turbine operations. Recommendations for start-up and shut-down procedures for the turbine operations that would produce the most acceptable velocity conditions in the repaired channel area downstream of the tailrace were made using these data. The depth soundings revealed that the stone protection material was quite stable. (District surveys reveal that no appreciable displacement has occurred during the subsequent months of operation of the powerhouse.) The flow velocities were found to concentrate along the right side of the channel as a result of uneven flow distribution from the draft tube bays and the asymmetrical geometry along the left side of the tailrace. Return flows were observed and found to concentrate along the left side of the channel except when all three turbines were operating. Operating recommendations for the turbines are made based on tailwater conditions, length of time of nonoperation of the powerhouse, and the velocity data obtained from the tests.
Rights:	Approved for public release; distribution is unlimited.
URI:	http://hdl.handle.net/11681/10683
Appears in Collections:	Miscellaneous Paper