著者

Bergan Carl W. Solemslie Bjørn W. Østby Petter Dahlhaug Ole G.

出版者

ターボ機械協会、韓国流体機械学会、中国工程熱物理学会、国際水理学会

雑誌

International Journal of Fluid Machinery and Systems

巻号頁・発行日

vol.11, no.2, pp.146-153, 2018

被引用文献数

20

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A hydrofoil resembling a high head Francis runner blade was submerged in a rectangular channel and attached to the walls in a fixed-beam configuration. The hydrofoil was excited by piezoelectric Macrofiber composite actuators (MFCs), and the vibration was measured at the trailing edge with Laser Doppler Vibrometry (LDV) and semiconductor strain gauges. The hydrofoil was exposed to water velocities ranging from 0 to 25 m/s. Lock-in occurred at approx. 11 m/s. The damping increased linearly with the water velocity, with a slope of 0.02 %/(m/s) below lock-in, and 0.13 %/(m/s) above lock-in. The natural frequency of the foil increased slightly with increasing water velocity below lock-in, due to the added stiffness of the passing water. Additionally, the natural frequency increased significantly when passing through lock-in, due to the vortex shedding phase shift.