Analysis of novel low specific speed pump designs

conference paper

English

Centrifugal pumps with very low specific speed present significant design challenges. Narrow blade channels, large surface area of hub and shroud discs relative to the blade area, and the presence of significant of blade channel vortices are typical features linked with the difficulty to achieve head and efficiency requirements for such designs. This paper presents an investigation of two novel designs of very low specific speed impellers: impeller having blades with very thick trailing edges and impeller with thick trailing edges and recirculating channels, which are bored along the impeller circumference. Numerical simulations and experimental measurements were used to study the flow dynamics of those new designs. It was shown that thick trailing edges suppress local eddies in the blade channels and decrease energy dissipation due to excessive swirling. Furthermore the recirculating channels will increase the circumferential velocity component on impeller outlet thus increasing the specific energy, albeit adversely affecting the hydraulic efficiency. Analysis of the energy dissipation in the volute showed that the number of the recirculating channels, their geometry and location, all have significant impact on the magnitude of dissipated energy and its distribution which in turn influences the shape of the head curve and the stability of the pump operation. Energy dissipation within whole pump interior (blade channels, volute, rotor-stator gaps) was also studied.

low specific speed pump, recirculating channels, energy dissipation

KLAS, R.; POCHYLÝ, F.; RUDOLF, P.

2014

1. 12. 2014

IOP Science

Spojené království Velké Británie a Severního Irska

1755-1315

IOP Conference Series: Earth and Environmental Science

22

1

United Kingdom of Great Britain and Northern Ireland

1

11

11

http://iopscience.iop.org/1755-1315/22/1/012010/pdf/1755-1315_22_1_012010.pdf