Numerical simulation and experimental analysis for cavitation in composite centrifugal pump

In order to study the cavitation of certain type of aerospace centrifugal pump, the multiphase model on the basis of Mixture was used together with cavitation model. The steady constant value of vapor-liquid phases was simulated under the condition of different negative pressures at inlet of water glycol inside the centrifugal pump with long and short composite impellers, and the cavitation test was conducted with different inlet pressures. The results indicate that the vaporization area expands along with the increase of negative pressure. In case the negative pressure at inlet is - 50kPa and the pressure difference at pump inlet and outlet is 155kPa,already approaching the 3% allowance of rated pressure difference, the pressure at outlet of centrifugal pump is 105kPa which is the critical cavitation pressure at outlet. In case the negative pressure at inlet is - 60kPa, the flow rate at outlet suddenly changes to 300L/h, the critical cavitation state occurs to the pump, and the inlet pressure is less than 10kPa that is the minimum pressure required in technical specification. Therefore, cavitation will not occur when the pump operates at its working range, and reliability of the value simulation in this paper is also verified.