Article
Engineering, Aerospace
Seid M. S. Mousavi, Seid H. Pourtakdoust
Summary: This study focuses on the control challenges and efficient performance in flapping flight, improving the controller to reduce the required control effort and significantly enhance control performance.
JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
(2022)
Article
Engineering, Mechanical
Yegane Azargoon, M. H. Djavareshkian
Summary: The aerodynamic performance of a fabricated eagle wing with a corrugated trailing edge was investigated in this study. Experimental and numerical analyses were conducted to compare the lift and thrust forces, lift-to-drag ratio, and input power between the eagle wing and a simplified wing. The results showed that the eagle wing with the corrugated trailing edge exhibited improved lift force and thrust force compared to the simplified wing. Numerical simulations further confirmed these findings.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
(2023)
Article
Biology
Chao Liu, Pengpeng Li, Fa Song, Eize J. Stamhuis, Jiyu Sun
Summary: The hovering flight action of a beetle species was studied to design a flapping-wing micro air vehicle (FWMAV). Various parameters were captured and a bioinspired wing and linkage mechanism flapping system were designed. Wind tunnel tests were conducted to optimize aerodynamic characteristics, paving the way for future development of beetle-mimicking FWMAVs.
COMPUTERS IN BIOLOGY AND MEDICINE
(2022)
Article
Engineering, Aerospace
Jiayu Wen, Yanguo Song, Huanjin Wang, Dong Han
Summary: This study presents a systematic approach to analyze the aerodynamic characteristics of tandem rotor forward autorotation considering rotor-to-rotor interference. The use of a single-rotor computational model as the baseline model demonstrates its effectiveness in comparison with wind tunnel test data. The study also investigates the influence of wind speed, rotor shaft angle, and collective pitch on steady-state rotor speed, revealing a non-linear variation that can cause thrust control reverse problems during flight operations. The flow field details of rotor-to-rotor interference are revealed by solving the Navier-Stokes equations, and a refined interference model is developed and validated against wind tunnel test data. This comprehensive methodology balances computational costs and accuracy, making it readily applicable to engineering practices.
Article
Engineering, Aerospace
Ernesto Sanchez-Laulhe, Ramon Fernandez-Feria, Anibal Ollero
Summary: A new forward-flight model for bird-like ornithopters is proposed in this study, which is validated with experimental data. This model provides a useful tool for the design, navigation, and trajectory planning and control of flapping wing UAVs.
Article
Engineering, Aerospace
Muhammad Yousaf Bhatti, Sang-Gil Lee, Jae-Hung Han
Summary: This paper presents an approach to analyze dynamic stability and develop trajectory-tracking controllers for flapping-wing micro air vehicles (FWMAV). A multibody dynamics simulation framework coupled with a modified quasi-steady aerodynamic model was used for stability analysis and gain matrices were obtained for different flight speeds using the linear-quadratic regulator technique. The controllers were successfully implemented for trajectory tracking with smooth control parameter updates to avoid discontinuities.
Article
Engineering, Mechanical
Kenneth Breuer, Mark Drela, Xiaozhou Fan, Matteo Di Luca
Summary: We introduce a new wind tunnel design that is ultra-compact and provides high flow quality. This tunnel has a smaller footprint compared to conventional tunnels with the same test section size and contraction ratio, resulting in lower material and construction costs. Several key features of this tunnel contribute to its small footprint, such as a two-dimensional main diffuser, a minimum-length contraction, and specially designed turning vanes. The tunnel demonstrates excellent flow quality with minimal mean flow variation and low freestream turbulence.
EXPERIMENTS IN FLUIDS
(2022)
Article
Engineering, Aerospace
C. Ruiz, J. A. Acosta, A. Ollero
Summary: The unsteady aerodynamics of flapping low-aspect-ratio ellipsoidal-wings in ornithopters is analyzed and modeled using three-dimensional Computational Fluid Dynamics (CFD) simulations. The results show that analytical models based on absence of viscosity and small perturbations are not appropriate for the range of interest, and a finite memory Volterra model is identified to predict the characteristics of forces and moments produced by the flapping wing.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Aerospace
Khanh Nguyen, Loan Thi Kim Au, Hoang-Vu Phan, Hoon Cheol Park
Summary: This paper compares the characteristics of hovering stability for two insect-inspired flapping-wing micro air vehicles (FW-MAVs) with different control mechanisms, and finds that the Stroke-Plane-Change (SPC) mechanism stabilizes faster and responds quicker than the Trailing-Edge-Change (TEC) mechanism, offering more agility for operation in cluttered environments.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Aerospace
Jianghao Wu, Xinyi Wu, Peng Tang, Yanlai Zhang, Chao Zhou
Summary: This study analyzed the hovering stability of a 30 g flapping-rotary-wing (FRW) prototype and found that it has two unstable modes: an unstable oscillatory mode and a slow divergence mode. The distinction between FRW and helicopters lies in the longitudinal-lateral coupling and rotational-vertical coupling in their modal characteristics.
Article
Chemistry, Multidisciplinary
Zhichao Zhu, Bifeng Song, Dong Xue
Summary: This paper optimized and validated the performance of large-scaled flapping wings in high-altitude environments through various methods, and proposed corresponding design suggestions such as increasing wing area, number of wing ribs, and selecting suitable materials. The study showed that in high-altitude environments, aircraft need to increase flight speed and frequency to compensate for the loss of lift and drag due to reduced air density, but this results in increased power consumption and reduced endurance.
APPLIED SCIENCES-BASEL
(2022)
Article
Thermodynamics
Ruiyang He, Xiaowei Deng, Yichun Li, Zhikun Dong, Xiaoxia Gao, Lin Lu, Yue Zhou, Jianzhong Wu, Hongxing Yang
Summary: An innovative three-dimensional yaw wake model is proposed to accurately predict the behavior of yawed wake, offering support for effective implementation of yaw control strategies.
Article
Ornithology
Herwig A. Grogger, Martin Gossar, Michael Makovec, Johannes Fritz, Katharina Neugebauer, Frederik Amann, Bernhard Voelkl
Summary: This paper provides a detailed description of the layout, design, and construction of a blower-type wind tunnel used for physiological bird flight experiments. The wind tunnel performs well according to numerical simulations and measurements of velocity distribution, with a relatively homogeneous flow and low turbulence intensity. The wind tunnel is able to accommodate large birds and has a flexible outlet nozzle to allow for various flight maneuvers.
JOURNAL OF ORNITHOLOGY
(2022)
Article
Engineering, Aerospace
Zdravko Terze, Marko Kasalo, Viktor Pandza, Dario Zlatar
Summary: Three recently approved space missions are heading to Venus to answer major questions about its atmosphere and geology. Direct measurements from Venus surface or within the atmosphere are needed to address many existing questions. To achieve this, a flapping wing vehicle concept optimized for Venus atmospheric flight is used. The computational model of the flapping wing vehicle is optimized to obtain energy efficient flight patterns in Venus surface atmospheric conditions. The study concludes that flapping wing propulsion is a feasible and effective concept for Venus exploration.
Article
Energy & Fuels
Emil Krog Kruse, Christian Bak, Anders Smaerup Olsen
Summary: The study found that increasing zigzag tape heights reduces maximum lift, while drag is less affected by zigzag tape height. Different sandpaper types have almost the same impact on reducing maximum lift, but drag increases with coarseness.
