Abstract：For the study of transient hydraulic characteristics and internal flow mechanism in centrifugal pumps from design conditions to non-design transition, three-dimensional modeling for centrifugal pumps internal flow through three-dimensional software pro/E , based on the Reynolds-averaged Navier-Stokes equations with the RNGk-εturbulence model and SIMPLEC algorithm, using full-cavitation model and considering effects on cavitations when the water is not dissolved gas, using the computational fluid dynamics software CFX to conducts the numerical simulation calculation of transient flow characteristics of variable operating conditions within whole flow passage of centrifugal pump , cavitation characteristics of centrifugal pump on the condition of inlet pressure continuously declining has been analyzed by numerical simulation, and compared it with experimental results.The results showed that: numerical simulation results and experimental results are the same trend. Flow analysis showed that: on the condition of variable flow transition, the pressure within the impeller value is not significantly increased, but the variable amplitude of pressure increases with the flow change; In the transition to high-volume, flow increase has little effect on the blade transient load, but in the transition to the low flow , the presence of secondary return and other factors a great effect on the blade transient load; In the transition process from the design conditions to cavitation conditions, at the critical NPSH, affected by the bubble phase blade transient load vary greatly, especially in the inlet it varies more; pressure and its amplitude occur sharp declines; the radial force roling on the impeller also get sharp increases.
2012, Vol. 31 
