Article
Engineering, Multidisciplinary
D. Diaz-Arriba, T. Jardin, N. Gourdain, F. Pons, L. David
Summary: This paper examines the applicability and accuracy of high-fidelity experimental and numerical approaches in analyzing three-dimensional flapping wings. It also investigates the impact of mass and frequency ratios on wing dynamics and flow physics.
BIOINSPIRATION & BIOMIMETICS
(2022)
Article
Engineering, Aerospace
Feng Liu Yang, Long Chen, Yan Qing Wang
Summary: This study presents an improved adaptive theoretical model for addressing the flexibility and fluid-structure interaction problem of insect and biomimetic wings in flapping-wing micro air vehicles (FWMAVs). The model considers the quantitative impact of spanwise bending on the stiffness design of flexible wings, resulting in better match with experimental measurements and faster convergence speed compared to traditional methods.
Article
Engineering, Marine
Hamayun Farooq, Muhammad Saif Ullah Khalid, Imran Akhtar, Arman Hemmati
Summary: This study investigates two-dimensional incompressible flows over elastically mounted foils and finds that introducing cubic damping terms significantly decreases the amplitude size without affecting the onset point of bifurcation. The performance metrics of passive systems for power generation applications were calculated.
Article
Engineering, Mechanical
Xin Shan, Onur Bilgen
Summary: This article introduces a method to achieve induced-strain flapping wings and fins using piezoelectric actuators, which can reduce system weight, energy consumption, and mechanical complexity. The author develops a lumped-parameter model to predict the dynamic behavior of the wings and investigates the coupling mechanisms and optimal parameters for maximizing performance.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Marine
Ming Luo, Zhigang Wu, Chao Yang
Summary: Due to their efficiency and low detectability, bionic underwater vehicles like Mantabot are becoming increasingly important in ocean exploration. However, research on manta-inspired robots is currently limited, with little focus on hydroelasticity and optimal design of flapping wings. This study presents a new method for analyzing aquatic flapping wings and explores the effects of flexibility and movement on wing dynamics.
Article
Mechanics
C. Martinez-Muriel, G. Arranz, M. Garcia-Villalba, O. Flores
Summary: In this study, we conducted direct numerical simulations of the flow around a spanwise-flexible wing in forward flight. By varying the effective stiffness and keeping the effective inertia constant, we found an optimal aerodynamic performance associated with a damped resonance phenomenon. This enhanced performance is attributed to larger effective angles of attack and a delayed development of the leading edge vortex.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Engineering, Aerospace
Longfei Zhao, Zongxia Jiao
Summary: In this work, a simple analytical tool for the efficient, optimal design of passive torsional flapping wings is proposed, and its effectiveness is validated through numerical simulation and experiments. The study demonstrates that optimizing wing torsional rigidity using the proposed method can significantly improve efficiency performance.
Article
Mechanics
Li Wang, Fang-Bao Tian, Hao Liu
Summary: This paper presents a numerical study on the aerodynamic performance of flapping wings in ultra-low-density fluid, focusing on the effects of compressibility on force production and efficiency. The study finds that rigid wings experience reduced lift coefficient and efficiency with increased Mach number. Various strategies, such as adjusting aspect ratio, stroke amplitude, and flexibility, are explored to achieve sufficient lift force. An optimized flexible wing is proposed and simulated, demonstrating significant improvements in lift coefficient and efficiency.
Article
Mechanics
Feng Liu Yang, Yan Qing Wang
Summary: This study presents a theoretical model to investigate the influence of thoracic muscles on insect flight. The results suggest that including thoracic muscles decreases lift and power, but improves lift efficiency, with minor effects on the movement trends of the flapping motion.
Article
Engineering, Mechanical
Yuping Wang, Xinyi He, Guoyi He, Qi Wang, Longsheng Chen, Xiaochen Liu
Summary: This paper investigates the aerodynamic performance of different technical airfoils and finds that increasing the flexibility of insect wings can significantly improve the aerodynamic forces at low Reynolds numbers. The results provide new insights into the formation and role of thrust in flapping maneuvering flight.
ACTA MECHANICA SINICA
(2022)
Article
Engineering, Mechanical
Fidel Fernandez, David Cleaver, Ismet Gursul
Summary: The study investigates the unsteady aerodynamics of two flexible cantilevered wings in transverse gusts. It reveals that at resonant conditions, the plunge angle due to bending deflections increases significantly, reducing the amplitude of the effective gust angle perceived by the wing.
JOURNAL OF FLUIDS AND STRUCTURES
(2022)
Article
Mechanics
Wouter G. van Veen, Johan L. van Leeuwen, Bas W. van Oudheusden, Florian T. Muijres
Summary: To generate aerodynamic forces for flight, insects move their wings back and forth at high frequencies. Existing models for aerodynamic forces often simplify the effects of wing-stroke rate and acceleration, which may not capture the complex unsteady aerodynamics. In this study, computational-fluid-dynamics simulations were used to explore the relationship between aerodynamic forces, flow dynamics, wing-stroke rate, wing-stroke acceleration, and wing-planform geometry. A novel unsteady aerodynamic force model was developed and calibrated, which includes improved versions of translational-force and added-mass force models, as well as a third component reflecting the delay in bound-circulation build-up during wing acceleration. The study shows that this effect can be modeled as a stroke-acceleration-dependent correction on the translational-force model. The new model was subsequently applied to realistic wing-beat kinematics of hovering Dipteran insects, demonstrating the substantial contribution of stroke-acceleration-related aerodynamic forces to lift and drag production.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Mechanical
Pierre-Olivier Descoteaux, Mathieu Olivier
Summary: This study presents a parametric investigation on Vertical-Axis Turbines (VAT) with chordwise-flexible blades, showing that flexibility can enhance efficiency at low tip-speed ratios and reduce drag at high tip-speed ratios. Moderate flexibilities can lead to a relative efficiency improvement of about 12% to 15% at tip-speed ratios of 2 and 6.
JOURNAL OF FLUIDS AND STRUCTURES
(2021)
Article
Engineering, Multidisciplinary
Yang Luo, Marvin Wright, Qing Xiao, Hong Yue, Guang Pan
Summary: Research has achieved motion control of swimming and station holding of a flexible plate through feedback control, effectively reducing energy consumption, with results showing successful motion control under different flow conditions.
BIOINSPIRATION & BIOMIMETICS
(2021)
Article
Mechanics
Qian Mao, Yingzheng Liu, Hyung Jin Sung
Summary: This study investigated the hydrodynamic mechanism of drag reduction by flapping a flexible filament behind a stationary cylinder using the penalty immersed boundary method. The effects of filament parameters on drag reduction were examined, and three distinct flapping modes were observed. The oscillation and undulation modes were found to be more beneficial for drag reduction than the vortex-dominated mode.
