West Closure Complex Pump Intake Model, New Orleans, Louisiana
ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS COASTAL AND HYDRAULICS LAB
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The WCC pump station intake was evaluated for intake performance using a 120-scale model of the approach channel, intake bays, contracted section, FSI, and pump column. Across the 11 different pump intakes, approach flow ranged from almost straight in to highly skewed. The original design of the contracted section was shown to have unacceptable submerged vortices. A fillet was added to eliminate a zone of low velocity and the submerged vortices were eliminated. The recommended design consists of no flow divider wall, longer dividing walls, and contracted sections with fillet added to low velocity zone. Tests were conducted with various pump operating combinations ranging from all pumps to single pumps to pumps on each end to odd versus even pumps. Tests were conducted for a range of approach flow skew ranging from large to straight in. Intake water level was varied from the minimum of EL 0.0 to the maximum of EL 7.0. Swirl in the pump intake was always less than the HI Standard of five degrees and was a maximum of three degrees when 50 percent of the trash rack on one side of the pump bay was completely blocked. Submerged vortices were acceptable with the fillet added to the contracted section. Time averaged velocity distribution in the pump throat met the HI Standard of 10 percent for all conditions including tests with 50 percent of the trash rack blocked on one side of the pump bay. Most measured velocity distributions met, and all but the trash rack blockage tests were within 1.0 percent of meeting, the more stringent velocity distribution requirement of five percent used in some pump intake studies. Testing showed that the combination of the contracted section and the FSI were effective in limiting swirl and producing an acceptable velocity for highly skewed approach flow conditions.
- Civil Engineering
- Pumps, Filters, Pipes, Tubing, Fittings and Valves