Passively adaptive wind energy harvester featuring a double-airfoil bluff body with adjustable attack angles. (15th February 2023)

• Record Type: Journal Article
• Authors: Liu, Jinlong; Bao, Bin; Chen, Jiatong; Wu, Yufei; Wang, Quan
• Is Part Of: Mechanical systems and signal processing. Volume 185(2023)
• Publication Date: 2023-02-15
• Subjects: Wind energy harvester -- Flow-induced vibration -- Double-airfoil bluff body -- Piezoelectric -- Passively adaptive; 2-D Two-dimensional -- 3-D Three-dimensional -- DABB Double-airfoil bluff body -- WSNs Wireless sensor networks -- FIV Flow-induced vibration -- FIV-PEHs FIV-based piezoelectric energy harvesters -- VIV Vortex-induced vibration -- VIV-PEHs VIV-based piezoelectric energy harvesters -- G-PEHs Galloping-based piezoelectric energy harvesters -- F-PEHs Flutter-based piezoelectric energy harvesters -- LCOs Limit cycle oscillations -- MFC Macro fiber composite; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2022.109814
• Languages: English
• ISSNs: 0888-3270

Abstract

Graphical abstract: Highlights: A passively adaptive wind energy harvester is proposed in a mode-switching way. Three typical working modes are realized by adopting the double-airfoil bluff body. An aero-electromechanical model is developed and verified for the proposed harvester. Positive aerodynamic work and dynamic stall are beneficial for energy harvesting. The proposed harvester is superior to the conventional galloping-based one. Abstract: In nature, the wind always fluctuates in magnitude. Hence, it is essential to consider the adaptability and durability of wind energy harvesters. This paper proposes a passively adaptive piezoelectric wind energy harvester with a double-airfoil bluff body to enhance performance subjected to time-varying wind velocity. The proposed double-airfoil bluff body is inspired by the fact that the attack angle can significantly affect the aerodynamic characteristics of the airfoil. An associated aero-electromechanical model is numerically developed to investigate the influence of the attack angle on the energy harvesting performance. Based on the aero-electromechanical model, the numerical results demonstrate three typical working modes that appear under different attack angles: vortex-induced vibration, galloping, and vibration suppression. These working modes can promise the proposed harvester to effectively and safely scavenge ambient wind energy. The physical mechanisms behind the three working modes are thoroughly explored given the work-energy principle and evolution of the vortex structure. The performance enhancement of the proposed harvester can be attributed to the positive aerodynamic work and an airfoil dynamic stall. Experiments are thereafter conducted to validate the theoretical results. Compared to the conventional galloping-based harvester with a square prism, the maximum voltage improvement percentage of the proposed harvester is over 62.3% within the investigated wind speed range when the attack angle is set to 10°.