Numerical analysis and experimental investigation on impeller-volute match characteristics

Impeller-volute match is an essential issue of pump dynamic characteristics and it is very important for the understanding of the flow features in the pumps and the vibration symptom of the device. Advanced performance diagnosis and smart operation and maintenance are profoundly dependent upon the perceiving of the rotor-stator interaction. In order to describe the interaction more comprehensively, the related flows were described by both theoretical approach and numerical simulations. Both velocity distribution and area-ratio aspect were theoretically indicated and a critical condition of non-shock criterion was proposed. Numerical efforts were therefore carried out and unveiled the flow regime as well as the pressure variations. The frequency properties of the pressure variations indicated that both the shaft rotation frequency and the blade passing frequency (BPF) dominated the contents, which implicitly demonstrated the accurate simulation work. Vibration content was lastly tested to validate the numerical results and the rotor-stator interaction effects. No significant shaft rotation contents appeared in the tested vibration signals due to the precise shaft support. Other than the blade passing frequency, both sub-synchronous and super-synchronous contents of BPFs appear under nearly all conditions. It is noted that the experimental means used here are able to get sufficient information of the pump operation.