Grant-in-Aid for Scientific Research (B).
|Research Institution||Yokohama National University|
KUROKAWA Jjunichi Yokohama National University, Faculty of Engineering, Professor, 工学部, 教授 (40017976)
鈴木 良治 富士電機(株), 研究課長
山本 和義 (株)荏原総合研究所, 研究所長
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)
MATSUI Jun Yokohama National University, Faculty of Engineering, Assistant Professor, 工学部, 助教授 (40251756)
IMAMURA Hiroshi Yokohama National University, Faculty of Engineering, Research Associate, 工学部, 助手 (30303077)
YAMAMOTO Kazuyoshi EBARA RESEARCH CO., LTD., General Manager
SUZUKI Ryoji VOITH FUJI CO., LTD, Manager
|Project Fiscal Year
1997 – 1999
Completed(Fiscal Year 1999)
|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)
|Keywords||Turbomachinery / Abnormal Flow Phenomena / Performance Instability / Rotating Stall / Shallow Groove / Pressure Gradient / 流体機械 / 異常流動現象 / 不安定性能 / 旋回失速 / 浅溝 / 圧力勾配 / 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|
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.