Qifa Lang, Yuqiao Zheng^*, Tiancai Cui, Chenglong Shi, Heyu Zhang

Energy Engineering, Vol.121, No.2, pp. 483-498, 2024, DOI:10.32604/ee.2023.042437

Abstract This work presents a novel approach to achieve nonlinear vibration response based on the Hamilton principle. We chose the 5-MW reference wind turbine which was established by the National Renewable Energy Laboratory (NREL), to research the effects of the nonlinear flap-wise vibration characteristics. The turbine wheel is simplified by treating the blade of a wind turbine as an Euler-Bernoulli beam, and the nonlinear flap-wise vibration characteristics of the wind turbine blades are discussed based on the simplification first. Then, the blade’s large-deflection flap-wise vibration governing equation is established by considering the nonlinear term involving the centrifugal force. Lastly, it is… More >

Hang Deng, Jimin Ye^*, Wei Li^*, Dongmei Huang

CMES-Computer Modeling in Engineering & Sciences, Vol.137, No.2, pp. 1731-1747, 2023, DOI:10.32604/cmes.2023.028334

Abstract In this paper, the response properties of galloping energy harvesters under bounded random parameter excitation are studied theoretically. The first-order approximate solution of the galloping energy harvester is derived by applying the multi-scales method. The expression for the largest Lyapunov exponent that determines the trivial solution is derived, and the corresponding simulation diagrams, including the largest Lyapunov exponent diagrams and time domain diagrams, verify our results. Then the steady-state response moments of the nontrivial solution are studied using the moment method, and the analytical expressions for the first-order and second-order moments of the voltage amplitude are obtained, respectively. The corresponding… More >