The Adaptive Blade Design and Evaluation of Wind Turbine

Abstract

This article explored the design method of the wind turbine blade being of flapping-twist adaptive performance and how to evaluate its feasibility and reliability according to the comprehensive factors. The results indicate that both spar cap and skin with off-axis carbon fiber can achieve the efficient flapping-twist coupling effect. Through overall investigation, the results show that the maximum fiber strains of tensile and compressive go up with increase of the off-axis angle, and the peak inter-laminar shear stress increase more rapidly. While, all of these evaluating indicators should be kept in the reference range for used materials. Moreover, when the off-axis angle increases, the peak Von Mises stress declines. In addition, the impact of natural frequencies on the blade design is proved to be insignificant. Finally, utilizing the medial axis laminates in the blade decoupled area is helpful to strengthen the blade fatigue resistivity.

Bend-Twist Coupling Design and Evaluation of Spar Cap of Wind Turbine Compliance Blade

“…At the same time, the full rotor effective coupling effect is taken into consideration. The coupling coefficient is calculated by introducing a weighted average method along the spanwise direction from formula 1~3 in document [5]. Cheng [1] discussed the influence of geometry shape of the D-spar on bend-twist coupling effect, concluding that the geometric effect can be neglected.…”

“…However, the result about the off-axis carbon fibers angle given in his study represented relatively independent design points, said that, 20° carbon with 0° glass, 20° carbon with −70° glass and a discontinuous 20° carbon fibers are assumed to be used only, which cannot be easily determined if there are more optimal configurations existed. The authors had investigated the impact of off-axis fiber angle in spar cap and skins of a 1.5MW adaptive blade previously [5], and applied the medial axis ply in the uncoupled area of the blade. The result proved that it had advantages in reducing the maximum stress and the stress cycles, increasing the fatigue lifetime.…”

“…The static and dynamic performance are calculated through three load steps: (1) Employ MPC184 rigid coupling element for bending moment and torque moment(shown in Fig. 1); Calculate the bend-twist coupling parameter and the equivalent bend stiffness by the method introduced in References [4] and [5]; (2) The blade are assumed to endure the load of critical wind of 50 m/s and gravity for checking the blade structural reliability, and apply SURF154 surface effect element to loading; (3) Analyze the blade first order out-of-plane and in-plane natural frequency. The performances are evaluated for each change of the off-axis angle and fraction of off-axis fibers.…”

“…Based on the previous study [5], the bend-twist coupling parameter is analyzed first in this paper, then the coupling effect is proved to be only related to the laminated materials by carrying out the spar cap of bend-twist coupling design. Finally, the static and dynamic performance of the blade made of off-axis carbon fibers is evaluated, which can provide a reference for compliance blade design.…”

Study of Yan Tai Train Station Parking Lot Improvement

“…The shopping center such as Times and Friend Square is in the south; the port freight terminal and store block is in the north; the Yan Tai international port is in the east; and Youth Road is in the west [1] , it has become the economic and transportation center. As the Lanyan double-line, Yanda ferry, and Delongyan local railways is built, the passengers' capacity of Yan Tai station will increase substantially, translocation among railway, water transport and road traffic will also further increase [2] . But there appearing a series of problems in Yan Tai railway station parking lot, such as parking chaos, crowded in peak parking and idle in low parking.…”