2004 Fiscal Year Final Research Report Summary
Study on Unsteady Aero-dynamic Load Analysis of Horizontal Axis Wind Turbine Rotor
| Project/Area Number |
15560136
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Nagoya University |
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Principal Investigator |
HASEGAWA Yutaka Nagoya University, Eco Topia Science Institute, Professor, エコトピア科学研究機構, 教授 (20198732)
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| Co-Investigator(Kenkyū-buntansha) |
KIKUYAMA Koji Nagoya University, Graduate School of Engineering, Professor, 工学研究科, 教授 (90023192)
IMAMURA Hiroshi Nagoya University, Graduate School of Engineering, Associate Professor, 工学研究科, 講師 (30303077)
ASAKURA Eiji Nagoya University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (90135327)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Numerical Analysis / Horizontal Axis Wind Turbine / Aero-Elasticity / Acceleration Potential Method / Aero-dynamic Load / Unsteady Flow / Tower / Inflow Condition |
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| Research Abstract |
Complex terrain has become attractive as the site proposed for WTGS(Wind Turbine Generator System). The turbulent intensity of the wind flow over the complex terrain is, however, much larger than that over flat terrain, and it brings about increased aerodynamic load on the wind turbine blades. Therefore it is important for the design of WTGS and wind turbine blades to estimate and/or to measure the turbulent characteristics of the wind over complex terrain correctly. It is also necessary to examine the effects of the unsteady flow conditions on the blade load fluctuation by means of a numerical calculation. In the present research, the following three projects have been performed.
A local angle of attack to HAWT rotor blade has been analyzed in the unsteady flow conditions, by means of numerical calculation based on the panel method. Yawed inflow condition was adopted for the calculation, and the spanwise distribution of the angle of attack (A.O.A.) is found to fluctuate in sinusoidal m
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anner when the yaw misalignment angle is small as much as 5〜15 deg. When the misalignment angle is increased to 30 degree, the fluctuation of A.O.A.shows high frequency component because of the dynamic stall effects.
The detailed wind measurements using multi wind-masts were also carried out at Shitara-Cho, Aichi in Japan during the period from November 19th in 2003 to March 23rd in 2004. The influence of the terrain slope on the wind has been examined by analyzing the vertical profile of mean velocity and the characteristics of the turbulence, such as the power spectrum and the coherence.
The existence of tower in horizontal axis wind turbine system has a large effect on surrounding fluid flow. In case of upwind wind turbines, the unsteady aerodynamic loads occur when the blades of a wind turbine are passing in front of the tower. The present research has also tried to produce a numerical method for calculating the effect of tower existence on the aerodynamic loads. For the calculation of aerodynamic loads on the rotor blades, an inviscid aerodynamic model based on the asymptotic acceleration potential method was adopted, which is capable of calculating the unsteady aerodynamic loads. In the model, the rotor blades are represented by spanwise and chordwise pressure distributions. The tower is represented by pressure distribution, in order to adapt the numerical model to that for the calculation of aerodynamic loads on the blades. Less
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