Conference Paper Two-Dimensional Aeroelastic Analysis of a Brimmed-Diffuser Shroud with Composite Material for a Wind Turbine

Kim, Taeyoung  ,  Nagai, Hiroto  ,  Ono, Kousei  ,  Uda, Nobuhide  ,  Ohya, Yuji  ,  Kim, Taeyoung  ,  永井, 弘人  ,  小野, 幸生  ,  宇田, 暢秀  ,  大屋, 裕二

A brimmed-diffuser shroud also known as a wind-lens is equipment to amplify output power in a wind turbine system by collecting and accelerating wind blowing through its rotor area. A small increase in wind speed accelerated by a wind-lens greatly raises output power from a wind power generator because output power is proportional to wind speed cubed. In spite of this advantage, its thin structure is prone to aeroelastic deformation and vibration. Especially, for a large-sized wind-lens, its wind resistance is also required to improve. In this study, aeroelastic response of the two dimensional brimmed-diffuser shroud for a 100kW wind power generator is computed under uniform wind conditions by using a two-dimensional Navier-Stokes code coupled with the equation of motion for the structure. Three types of material were applied to a diffuser model: aluminum alloy, CFRP laminate and sandwich structure with CFRP layers and PET foam. The density of the sandwich structure is lowest among the three materials. The weight of the three models is kept same by adjusting their thickness for analysis, and the model of the sandwich structure has become thickest. We verified that resonance occurs in the models when a vortex frequency matches a natural frequency of the structure. Besides, we confirmed that vibrating motion in resonance depends on a dominant mode shape. As a result, the sandwich model has the least vibrating motion in resonance because of high rigidity by its thickness. Considering the results, our estimation of critical wind speed using a Strouhal number is found to agree well with the aeroelastic responses.
Meeting Information: First International Symposium on Flutter and its Application (May 15-17, 2016. Mielparque-tokyo), Minato-ku, Tokyo, Japan
Physical characteristics: Original contains color illustrations
形態: カラー図版あり

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