In 1974 Tibetan savant Rtsis--dpon Zhwa -- sgab -- pa Dbang--phyug bde--ldan published acollection of historical works selected from his private holding. One of the texts made available as aresult is a short account o...In 1974 Tibetan savant Rtsis--dpon Zhwa -- sgab -- pa Dbang--phyug bde--ldan published acollection of historical works selected from his private holding. One of the texts made available as aresult is a short account of the Byang La--stod area in Central Tibet, the Sde--pa G. yas--ro Byang--pa’ i rgyag--rabs rin -- po -- che bstar ba(hereafter Byang -- pa’ i rgyal -- rabs; it is comprised oftwenty--two folia of which six [ff. 16v -- 21v; the colophon is on ff. 21v--22r] deal with the ab-展开更多
To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated accordi...To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects, and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.展开更多
文摘In 1974 Tibetan savant Rtsis--dpon Zhwa -- sgab -- pa Dbang--phyug bde--ldan published acollection of historical works selected from his private holding. One of the texts made available as aresult is a short account of the Byang La--stod area in Central Tibet, the Sde--pa G. yas--ro Byang--pa’ i rgyag--rabs rin -- po -- che bstar ba(hereafter Byang -- pa’ i rgyal -- rabs; it is comprised oftwenty--two folia of which six [ff. 16v -- 21v; the colophon is on ff. 21v--22r] deal with the ab-
基金supported by the National Natural Science Foundation of China (No. 50708015)the Program for New Century Excellent Talents in University (No. NCET-06-0270), China
文摘To analyze wind-induced response characteristics of a wind turbine tower more accurately, the blade-tower coupling effect was investigated. The mean wind velocity of the rotating blades and tower was simulated according to wind shear effects, and the fluctuating wind velocity time series of the wind turbine were simulated by a harmony superposition method. A dynamic finite element method (FEM) was used to calculate the wind-induced response of the blades and tower. Wind-induced responses of the tower were calculated in two cases (one included the blade-tower coupling effect, and the other only added the mass of blades and the hub at the top of the tower), and then the maximal displacements at the top of the tower of the tow cases were compared with each other. As a result of the influence of the blade-tower coupling effect and the total base shear of the blades, the maximal displacement of the first case increased nearly by 300% compared to the second case. To obtain more precise analysis, the blade-tower coupling effect and the total base shear of the blades should be considered simultaneously in the design of wind turbine towers.
