Cavitation Instabilities in Inducers that Employ A Stability Control Device
Description
High suction performance inducers are designed to operate at very low pressures with significant cavitation on the blades, particularly at a the design flow coefficient. Deviation from the design flow coefficient leads to large backflow at the blade leading edge that generates cavitation events like rotating cavitation and cavitation surge, which can lead to pump failure. It has been shown that the implementation of a stability control device (SCD) can increase the operational range allowing the inducer to operate without backflow even at off-design flow coefficients. This is achieved by a local increase in mass flow rate at the leading edge when the SCD is in place. While the SCD has shown to decrease rotordynamic forces and increase the pump suction performance, new cavitation events have also been discovered when the SCD is implemented. In some cases, a cavitation surge can develop in the SCD creating large fluctuations in the mass flow rate and pressure in the pump. In some cases significant blade instabilities have developed. These cavitation instabilities are sensitive to the SCD and inducer geometry and the instabilities need to be addressed to optimize the design of high suction pumps that employ an SCD.
Cavitation Instabilities in Inducers that Employ A Stability Control Device
The Leonardo Event Center
High suction performance inducers are designed to operate at very low pressures with significant cavitation on the blades, particularly at a the design flow coefficient. Deviation from the design flow coefficient leads to large backflow at the blade leading edge that generates cavitation events like rotating cavitation and cavitation surge, which can lead to pump failure. It has been shown that the implementation of a stability control device (SCD) can increase the operational range allowing the inducer to operate without backflow even at off-design flow coefficients. This is achieved by a local increase in mass flow rate at the leading edge when the SCD is in place. While the SCD has shown to decrease rotordynamic forces and increase the pump suction performance, new cavitation events have also been discovered when the SCD is implemented. In some cases, a cavitation surge can develop in the SCD creating large fluctuations in the mass flow rate and pressure in the pump. In some cases significant blade instabilities have developed. These cavitation instabilities are sensitive to the SCD and inducer geometry and the instabilities need to be addressed to optimize the design of high suction pumps that employ an SCD.