| 摘要 |
The pumping performance of a centrifugal pump is improved in a cost-effective manner by a pumping component, e.g. impeller or diffuser 54, having one or more vanes 58, defining fluid flow paths, provided with a respective through passage 60 such that an end of the passage is exposed to a low energy flow, i.e. secondary flow, region. The or each passage 60 enables the flow of a small amount of fluid from the low energy region to an opposite side of the vane 58 to reduce the secondary flow effects and improve pumping efficiency. The passage(s) 60 can be at junction(s) with a hub 74 and shaped so that the impeller or diffuser 54 can be produced by sand casting without further forming of the passage(s). |
