The relation between internal flow and loss mechanism of unshrouded runners

Shunsuke Nagata*, Tatsuya Irie, Kazuyoshi Miyagawa


研究成果: Conference article査読


High efficiency, low-cost, and reliable hydraulic turbines are in high demand for hydroelectric power generation, especially in medium and small-scale power plants. The authors' laboratory has been developing unshrouded, i.e., band-opened runners of turbines to meet the demand. Those runners feature highly efficient performance and less expensive manufacturing costs produced by cutting, not by casting. For the sake of developing further improved unshrouded runners, it is necessary to understand their loss mechanism in detail. Therefore, in this study, the internal flow and the loss mechanism are investigated experimentally and computationally, with two different specific speed hydro turbine runners. First, Euler's theoretical head on each runner is discussed to identify if they are influenced by the distinct specific speed. It demonstrated that the low specific speed turbine consumes greater potential energy in centrifugal force. Secondary, the loss mechanism in the unshrouded runners is investigated. The result showed that the dominant loss is caused by a tip leakage vortex developed by the collision of a leakage flow at the tip clearance and a secondary flow.

ジャーナルJournal of Physics: Conference Series
出版ステータスPublished - 2022 5月 6
イベント16th Asian International Conference on Fluid Machinery, AICFM 2021 - Virtual, Online
継続期間: 2021 9月 132021 9月 15

ASJC Scopus subject areas

  • 物理学および天文学(全般)


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