Hydrodynamic Design Considerations for Hydroacoustic Facilities: Part II—Pump Design Factors

The St. Anthony Falls Hydraulic Laboratory has been involved in the hydrodynamic design of large cavitation facilities, which require a high performance axial flow pump that is cavitation free to meet stringent design conditions. As cavitation has been shown to be the largest noise source in an otherwise well designed facility, it must be eliminated for the design range of flow conditions. To reduce the possibility of blade cavitation it is desirable to have a near uniform, or at least, a near symmetrical approach velocity distribution at the pump inlet. The design of flow facilities to achieve such an inflow was the subject of extensive investigations. These investigations consisted of both numerical and physical modeling of critical components in the test loop. The influence of these components, which included the contraction, diffuser, and turning vanes was carefully documented. The combination of the two modeling techniques will be demonstrated as an effective design tool for a high performance, hydrodynamic test facility.