Suppression of standing waves generated on the water flow surface for turbine performance improvement

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06072
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Shinshu University
• Principal Investigator: Iio Shouichiro 信州大学, 学術研究院工学系, 准教授 (80377647)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 液膜流 / 遠心力不安定 / 定在波 / ゲルトラー数 / 水車

Outline of Final Research Achievements

This study was focused on the generating mechanism and suppression method of standing waves along the streamwise direction on water free surface through a convex open channel. The surface deformation pattern was captured, and the flow velocity was measured. From these experimental results, the following remarks can be drawn: The water thickness on the convex part is correlated with the streamwise velocity, especially for that the relationship shows good agreement with the distribution of Gertler number. Positive correlation can be recognized between the water thickness and Weber number. When the relative velocity between the water flow and the channel surface was changed by using moving belt, there was no cleat difference in the occurrence of the standing waves.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

再生可能エネルギーの中でもエネルギー密度と安定性に優れる水力発電に関して，水車への導水部である凸面を有する導水路において発生する定在波が水車効率を低下させる．本研究はその定在波の発生機構の解明とその抑制方法に関する知見を獲得することを目的としている．実験において水流表面の定在波の，水流速度，水流厚み，凸面部の曲率半径等への依存性を明らかにし，抑制方法につながる知見を獲得することができた．