Abstract
The centrifugal pump is one of the most important pieces of energy-consuming equipment in various hydraulic engineering applications. This paper takes a low specific speed centrifugal pump as the research object. Based on the research method combining numerical calculation and experimental verification, the influence of the gap drainage structure on the performance of the low specific speed centrifugal pump and its internal flow field distribution were investigated. The flow field inside the low specific speed centrifugal pump impeller under different gap widths was studied. The comparison between the numerical calculation results and the experimental results confirms that the numerical calculations in this paper have high accuracy. It was found that the gap drainage will reduce the head of the low specific speed centrifugal pump, but increase its hydraulic efficiency. Using a smaller gap width could greatly improve the performance of the low specific speed centrifugal pump on the basis of a slight reduction in the head. The high-pressure leakage flow at the gap flows from the blade pressure surface to the suction surface can effectively suppress the low-pressure area at the impeller inlet. The flow rate of the high-pressure leakage flow increases with the gap width. Excessive gap width may cause a low-pressure zone at the inlet of the previous flow passage. These results could serve as a reference for the subsequent gap design to further improve the operating stability of the low specific speed centrifugal pump.
Highlights
With the development of modern industry, many actual operating conditions put forward high-head, low-flow performance requirements for centrifugal pumps [1,2,3]
The low specific speed pump is a centrifugal pump with specific speed less than 80, has a small flow coefficient, and requires a small blade outlet angle
Three-dimensional modeling is the first step in numerical calculation
Summary
With the development of modern industry, many actual operating conditions put forward high-head, low-flow performance requirements for centrifugal pumps [1,2,3]. The performance requirements of low specific speed centrifugal pumps are continuously improved and their scope of use continues to expand. They are widely used in aerospace, petrochemical, water conservancy, and hydropower, among others [4,5,6]. There could be complex flow phenomena such as strong secondary flow and flow separation in the flow passage, which could damage the flow stability and cause serious energy loss and further reduce the performance of the low specific speed centrifugal pump [10,11,12,13]. How to improve the performance of the low specific speed centrifugal pump and increase its operational stability has become a research hotspot and a difficulty in the field [14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
