Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

Alejandro Ortega Ancel; Rodney Eastwood; Daniel Vogt; Carter Ithier; Michael Smith; Rob Wood; Mirko Kovač

doi:10.1098/rsfs.2016.0087

Aerodynamic evaluation of wing shape and wing orientation in four butterfly species using numerical simulations and a low-speed wind tunnel, and its implications for the design of flying micro-robots

Interface Focus ◽

10.1098/rsfs.2016.0087 ◽

2017 ◽

Vol 7 (1) ◽

pp. 20160087 ◽

Cited By ~ 16

Author(s):

Alejandro Ortega Ancel ◽

Rodney Eastwood ◽

Daniel Vogt ◽

Carter Ithier ◽

Michael Smith ◽

...

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Small Body ◽

Butterfly Species ◽

Butterfly Wing ◽

Long Distance ◽

Energetic Costs ◽

Low Speed ◽

Body Sizes ◽

Low Speed Wind Tunnel

Many insects are well adapted to long-distance migration despite the larger energetic costs of flight for small body sizes. To optimize wing design for next-generation flying micro-robots, we analyse butterfly wing shapes and wing orientations at full scale using numerical simulations and in a low-speed wind tunnel at 2, 3.5 and 5 m s −1 . The results indicate that wing orientations which maximize wing span lead to the highest glide performance, with lift to drag ratios up to 6.28, while spreading the fore-wings forward can increase the maximum lift produced and thus improve versatility. We discuss the implications for flying micro-robots and how the results assist in understanding the behaviour of the butterfly species tested.

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Aerodynamic Performance of Hex-Rotor UAV Considering the Horizontal Airflow

Applied Sciences ◽

10.3390/app9224797 ◽

2019 ◽

Vol 9 (22) ◽

pp. 4797

Author(s):

Yao Lei ◽

Mingxin Cheng

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Aerodynamic Performance ◽

Wind Tunnel Experiments ◽

Low Speed ◽

Pressure Distributions ◽

Hover Performance ◽

Power Loading ◽

Aerial Vehicle ◽

Low Speed Wind Tunnel

In this paper, the aerodynamic performance of a Hex-rotor unmanned aerial vehicle (UAV) with different rotational speeds (1500–2300 RPM) considering the horizontal airflow conditions is analyzed by both simulations and experiments. A low-speed wind tunnel experiments platform is applied to measure the thrust, torque, and power consumption of a Hex-rotor UAV with different rotational speeds in horizontal airflow, which varied from 0 m/s–4 m/s. First, this paper introduces the effect of horizontal airflow on a UAV. Then, the low-speed wind tunnel experiments were carried out on a Hex-rotor UAV (D/L = 0.56) with different horizontal velocities to determine the hover performance. Finally, numerical simulations were obtained with the streamline distributions, pressure distributions, velocity contour, and vortex distributions at different horizontal airflow conditions to describe the aerodynamic interference effect of different horizontal airflows. Combined with the experimental results and numerical simulations results, the horizontal airflow proved to have a significant influence on the aerodynamic performance of the Hex-rotor UAV with an increase in thrust and power. Indeed, the streamlines in the flow field were coupled to each other at the presence of the incoming airflow. Especially when the incoming airflow was larger, the Hex-rotor UAV could properly use low-speed flight to maintain high power loading. Finally, it is inferred that the aerodynamic performance of the Hex-rotor UAV is also related to the movement and deformation of the vortex at the tip of the rotor.

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