| Project/Area Number |
09555062
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Fluid engineering
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| Research Institution | Yokohama National University |
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Principal Investigator |
KUROKAWA Jjunichi Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (40017976)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Kazuyoshi EBARA RESEARCH CO., LTD., General Manager, 研究所長
IMAMURA Hiroshi Yokohama National University, Faculty of Engineering, Research Associate, 工学部, 助手 (30303077)
MATSUI Jun Yokohama National University, Faculty of Engineering, Assistant Professor, 工学部, 助教授 (40251756)
SUZUKI Ryoji VOITH FUJI CO., LTD, Manager, 研究課長
吉井 総介 三菱重工業(株), 研究次長
北洞 貴也 横浜国立大学, 工学部, 助手 (30204910)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥12,000,000 (Direct Cost: ¥12,000,000)
Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1998: ¥4,500,000 (Direct Cost: ¥4,500,000)
Fiscal Year 1997: ¥4,900,000 (Direct Cost: ¥4,900,000)
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| Keywords | Turbomachinery / Abnormal Flow Phenomena / Performance Instability / Rotating Stall / Shallow Groove / Pressure Gradient / 浅構 / ディフューザ / 極低比速度 / 右上がり不安定性能 / 放射状態 / ターボ機械 / スクールブレ-カ / パッシブコントロール / ドラフトサージ / 旋回流 |
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| Research Abstract |
The objective of this study is to suppress and control the abnormal phenomena in turbomachinery due to the swirl flow such as a rotating stall in the vaned and vanless diffuser, a performance-curve instability caused by the reverse flow at the impeller inlet in the centrifugal, mixed and axial pumps, a rotating cavitation in the pumps and the draft surge of water turbine by use of the angular momentum defect of flow in the shallow grooves mounted parallel to the pressure gradient on the casing wall.
In this study, the following results and remarks have been obtained.
・ The performance curve instability characterized by a local dent in head-capacity curve or an uprising head-capacity curve in mixed flow pump has been suppressed and controlled by use of the shallow grooves located with proper dimension.
・ The suppression of rotating stall in the vaneless diffuser has been obtained and made clear the mechanism of reducing a swirl by the grooves theoretically and experimentally.
・ By the optimization of groove dimension, the rotating stall of the vaned diffuser has been suppressed completely.
・ To reveal the possibility and the effect of the shallow grooves on controlling and reducing the swirl intensity of a runner outlet flow, a steady rotational flow in a conical diffuser of divergent angle of 30 degree was studied experimentally. The results showed that the shallow grooves with adequate dimensions can reduce the swirl rate of the main flow 85% of the inlet swirl without additional hydraulic loss.
This study showed that the abnormal flow phenomena in turbomachinery can control without decreasing the efficiency by use of the shallow grooves mounted parallel to the pressure gradient on the casing wall.
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