Flow instability in off design condition of vaned and vaneless diffuser centrifugal pump

Hideto Hiramatsu, Akiha Shibata, Shutaro Komaki, Kazuyoshi Miyagawa, Takeshi Sano

Research output: Contribution to conferencePaper

Abstract

In this study, the performance and the internal flow of one stage model centrifugal pump with both vaned and vaneless diffuser were investigated. To measure the internal flow of the diffuser and the impeller easily, air was used in this pump test. As a result of measuring pressure fluctuation, the rotating stall was observed in the vaned and vaneless diffuser. We clarified the generating mechanism and characteristics of the rotating stall in the diffuser and the difference between the unsteady flow fields in both diffusers. In case of the vaned diffuser, the number of rotating stall cells were 4 in the diffuser and the cell propagation speed ratio was about 5 percent of the impeller rotating speed. On the other hand, in case of the vaneless diffuser, the cell number was 2, and the propagation speed ratio was about 10 percent of that. These phenomena in both diffuser pumps were simulated by unsteady 2D and 3D CFD computations. By using these computations, the vortex at the trailing edge of the diffuser vanes blocked the flow and induced separate flow at the leading edge resulted in the rotating stall. This research indicated that these vortices induced the total pressure loss increasing. Also, the rotating stall was found not only in the diffuser but also in the impeller by the flow simulation of the vaneless diffuser. And it was confirmed that the vortices at the impeller trailing edge and leading edge in the stall cells cause the total pressure loss.

Original languageEnglish
DOIs
Publication statusPublished - 2015 Jan 1
EventASME/JSME/KSME 2015 Joint Fluids Engineering Conference, AJKFluids 2015 - Seoul, Korea, Republic of
Duration: 2015 Jul 262015 Jul 31

Other

OtherASME/JSME/KSME 2015 Joint Fluids Engineering Conference, AJKFluids 2015
CountryKorea, Republic of
CitySeoul
Period15/7/2615/7/31

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Fingerprint Dive into the research topics of 'Flow instability in off design condition of vaned and vaneless diffuser centrifugal pump'. Together they form a unique fingerprint.

  • Cite this

    Hiramatsu, H., Shibata, A., Komaki, S., Miyagawa, K., & Sano, T. (2015). Flow instability in off design condition of vaned and vaneless diffuser centrifugal pump. Paper presented at ASME/JSME/KSME 2015 Joint Fluids Engineering Conference, AJKFluids 2015, Seoul, Korea, Republic of. https://doi.org/10.1115/ajkfluids2015-33353