著者

Chirag Trivedi Ole Gunnar Dahlhaug

出版者

Turbomachinery Society of Japan, Korean Society for Fluid Machinery, Chinese Society of Engineering Thermophysics, IAHR

雑誌

International Journal of Fluid Machinery and Systems (ISSN:18829554)

巻号頁・発行日

vol.12, no.4, pp.345-367, 2019 (Released:2019-12-24)

参考文献数

216

被引用文献数

13

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The paper critically reviews the verification and validation (VV) techniques applied to investigate hydraulic turbines. Although there are well-established standards such as AIAA G-077-1998 and ERCOFTAC guide for turbulence modelling, majority of studies conducted on the turbines are lacking of systematic VV. Results without proper VV serve no purpose for safe and reliable designs of turbines. Available standards/guide are for general-purpose industrial applications and have limited scope. Customized VV procedure for the turbine applications is essential to create trust on the obtained results. The present review discusses how available standards/guide can be used to determine uncertainty/error and to demonstrate the credibility of results. The review includes several aspects of VV such as effect of discretization schemes, iterative error, convergence criteria, time-step sizing and impact of passage modeling approaches on the results. Further, how numerical results mislead the user and its implications are addressed. In the last, open questions on turbine modelling and recommendations on prospective numerical studies are discussed.

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.