Bonneville First Powerhouse ERDC Turbine Operating Range Investigation

As part of the Turbine Survival Program implemented by U.S. Army Corps of Engineers, Portland and Walla Walla Districts in the Northwestern Division, this study investigates all potential fish passage routes through the Bonneville First Powerhouse B1, minimum gap runner MGR, and draft tube using a 125 physical turbine model. Fish passage at on-cam turbine operations is investigated throughout the complete operating range of the B1 MGR to help determine the target operating range for minimizing turbine effects on fish passing through the B1 powerhouse. Relative effects of blade contact, shear, stay vane and wicket passage, draft tube conditions, and effects on egress were determined across the entire turbine operational range at 55 ft head. This includes operation within and beyond the current 1 operating zone. Results from these model investigations indicate that that steeper blade angles BAs if operated at peak efficiency for that subject blade angle provide for better passage conditions for fish. Fewer severe contacts with the turbine runner and less severe change in direction occur at steeper BAs. The draft tube elbow performs better at steeper BAs, and the quality of flow exiting the draft tube is better at steeper BAs. In addition, there are indications that egress conditions may be better at steeper BAs.