Article
Chemistry, Multidisciplinary
Hualong Xie, Yuqing Feng, Junfeng Zhao, Xiaofei Ma
Summary: This paper studies the deploying behavior of bird tail feathers, summarizes the bionic principles that can be used for antenna design, and proposes a new parabolic antenna structure that imitates the feather deploying of birds. The kinematic model of the deployable mechanism is established and analyzed, and the deployment trajectories and spatial arrangement of the antenna are determined.
APPLIED SCIENCES-BASEL
(2023)
Article
Mechanics
Zhe Hui, Gui Cheng, Gang Chen
Summary: The research demonstrates that increasing the distribution density of feather-shaped winglets can effectively suppress tip-vortex structures in the wake region, but increasing the gap weakens this suppression effect. The variation of distribution density significantly affects lift-drag efficiency.
Article
Biotechnology & Applied Microbiology
Shihao Zheng, Xi Liang, Jiayong Li, Yanyan Liu, Jun Tang
Summary: This study proposes a novel approach for drag reduction in the shipping industry by emulating the ridge structure of killer whale skin. The transverse bionic groove surface demonstrates promising drag reduction outcomes across diverse flow conditions.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2023)
Article
Acoustics
Min Li, Jiu Hui Wu, Xiao Yang Yuan
Summary: A new bionic metasurface structure is proposed for aerodynamic noise control on the vehicle body surface, which utilizes wall suction and slip effects to control and delay the separation of the boundary layer, effectively reducing noise levels within the frequency range of 450-1000 Hz.
Article
Engineering, Multidisciplinary
Yongqiang Ge, Jiamin He, Jin Guo, Peihao Zhang, Hao Wang, Ziqiang Ren, Xiaoling Le, Ying Wang, Yuhong Wang, Jiawang Chen
Summary: A new bionic sampler tube (BST) with a non-smooth surface was designed for low-disturbance and rapid sampling. The sampling performance of the BST was studied through theoretical calculations, numerical simulations, and experimental tests. The results showed that the BST improved sampling performance and reduced adhesion and drag.
JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE A
(2023)
Article
Engineering, Aerospace
Zhiping Li, Long He, Yueren Zuo, Bo Meng
Summary: Previous studies have found that the aspect ratio (AR) of a transverse groove significantly affects the stability of the boundary vortex and the rate of drag reduction. However, there is currently no theoretical model that describes the relationship between AR and the stability of the boundary vortex, making it difficult to develop a method to determine the optimal AR. In this study, an image vortex model is used to describe the velocity potential of the groove sidewalls, establishing the relationship between AR and induced velocity. The velocity profile of the migration flow is obtained by decomposing the total velocity inside the groove, allowing for the relationship between AR and migration velocity to be established. An analytical solution for the optimal AR is derived based on the kinematic condition for boundary vortex stability, and the motion forms of the boundary vortex at other ARs are discussed. The stability of the boundary vortex at the optimal AR and the corresponding drag reduction rate are verified through large eddy simulations. At other ARs, the motion forms of the boundary vortex are characterized by vortex shedding and vortex sloshing, with corresponding drag reduction rates smaller than those for vortex stability.
Article
Engineering, Multidisciplinary
Xixing He, Yihe Liu, Haiyang Zhan, Yahua Liu, Lei Zhao, Shile Feng
Summary: A bionic flounder two-tier structural surface (BFTSS) inspired by flounder ctenoid scales can significantly reduce skin friction drag in both forward and backward directions. This bidirectional drag reduction is achieved through the synergistic effects of the two-tier structures, which distort the boundary layer flow and mitigate viscous shear, as well as promote flow separation to relieve the pressure gradient in the viscous sublayer. The BFTSS technology has potential applications in reducing energy consumption in ships, underwater vessels, and pipeline transport.
Article
Materials Science, Coatings & Films
Yonghua Wang, Zhongbin Zhang, Jinkai Xu, Huadong Yu
Summary: This study extracted and produced four bionic fish-scale models based on the body of Sciaenops ocellatus, and introduced a simple, quick and low-cost method using laser for fabricating the bionic fish-scale surface on aluminum alloy. By controlling the laser path density and processing times, fish-scale morphology with inclined surface was obtained. Wettability tests showed that all samples were hydrophobic, with the sample at 100% zoom ratio demonstrating excellent super-hydrophobicity and low adhesion. Drag reduction performance was tested on the sample with 100% zoom ratio, showing different drag reduction values under different flow conditions, with a drag reduction rate of 4.814% under laminar conditions.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Mechanics
Longyin Jiao, J. M. Floryan
Summary: Analysis of pressure losses in laminar, pressure-gradient-driven channel flows with wall transpiration shows that reduction in effective channel opening, nonlinear streaming, and elimination of direct contact between fluid and walls influence these losses. Proper selection of transpiration pattern can reduce pressure losses, with nonlinear streaming being the dominant effect. Increasing transpiration at both walls can further decrease losses when in proper relative position, but concentrating transpiration at a single wave number achieves the largest reduction. The use of transpiration increases energy cost of flow, with optimization of conditions leading to minimization of this cost for most effective propulsion augmentation.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Nanoscience & Nanotechnology
Dan Liu, Jiaao Cheng, Bifeng Song, Wenqing Yang, Dong Xue
Summary: In this paper, numerical simulations were conducted to examine the influence of wingtip slots on six wings, and the results showed that wingtip slots can significantly increase aerodynamic force and improve maximum lift-to-drag ratio. The vortex structures of slotted wings show expressive changes in the tip vortex. An innovative bionic slotted wing with dynamic wingtip was proposed, which achieved the optimal time-averaged force through the aerodynamic interaction among multiple winglets.
Article
Chemistry, Applied
Liguo Qin, Shan Lu, Jianbo Liu, Yuhao Wu, Zeyu Ma, Fagla Jules Mawignon, Guangneng Dong
Summary: The study proposes a strategy of combining microstructures and Benzotriazole (BTA) to design an efficient and environmentally friendly antifouling coating. The coating with shark skin shield scale structure and BTA as a corrosion inhibitor exhibits significantly reduced friction coefficient, improved anti-corrosion performance, and increased drag reduction.
PROGRESS IN ORGANIC COATINGS
(2022)
Article
Metallurgy & Metallurgical Engineering
Jie Zhang, Yan-si Ding, Yi-han Wang, Shuai Han, Feng-yi Huang, Hai Deng, Zheng-wei Chen, Guang-jun Gao
Summary: Improving the pressure distribution in the pantograph area by installing a bionic elytron (deflector) can effectively reduce train aerodynamic drag. The installation of deflectors resulted in a significant reduction in aerodynamic drag force, with maximum reductions of 84.5% in pantograph I region and 25.0% in pantograph II region. Installing deflectors in both pantograph areas achieved a total drag reduction of 49.6% in pantographs I and II areas.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Engineering, Manufacturing
Guijian Xiao, Yi He, Yun Huang, Shui He, Wenxi Wang, Yuan Wu
Summary: The research delves into the drag reduction mechanism of bionic microstructure processed by belt grinding and sets up three groups of typical belt grinding bionic microstructures for CFD simulation to calculate drag reduction values. The experiment on aero-engine blade validates the airflow dynamics of drag reduction, with the results indicating that wave ribs outperform V-ribs and trapezoidal ribs in terms of drag reduction and increasing the size of bionic microstructure can improve airflow dynamic performance.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE
(2021)
Article
Engineering, Multidisciplinary
Qian Li, Huan Shen, Qingfei Han, Aihong Ji, Zhendong Dai, Stanislav N. Gorb
Summary: This study investigates the interaction between flight feathers of birds and air flow, and reveals that the integrity of feathers plays a crucial role in drag and drag reduction performance. Intact secondary feathers show better drag reduction capability at low wind speeds. The appropriate permeability of intact feathers prevents flow separation and allows feathers to withstand larger aerodynamic forces at high wind speeds.
JOURNAL OF BIONIC ENGINEERING
(2022)
Article
Engineering, Biomedical
Zhou Li, Yunqing Gu, Lingzhi Yu, Zhuofan Yin, Wenting Wang, Denghao Wu, Jiegang Mou, Shuihua Zheng
Summary: This study aimed to investigate blood flow in bionic artificial blood vessels and explored the drag reduction characteristics of V-shaped groove microstructures in artificial blood vessels to reduce resistance. By varying flow velocity, groove width, and groove depth, the effect of different conditions on drag reduction was analyzed, and the flow field characteristics and drag reduction effect of the V-shaped groove microstructure were obtained. The study also examined the impact of velocity and groove size on drag reduction to understand the mechanism and variation law of the V-shaped groove. Results showed that the resistance reduction rate of the V-shaped groove microstructure decreased with increasing blood flow velocity, increased with increasing groove width, and increased and then decreased with increasing groove depth. The velocity range used in the study was 0.3-0.6 m/s, groove width varied from 0 to 0.3 mm, and groove depth varied from 0 to 0.3 mm.
APPLIED BIONICS AND BIOMECHANICS
(2023)
