Search

Your search keyword '"Park, Hoon"' showing total 38 results
Start Over Author "Park, Hoon" Journal journal of bionic engineering
38 results on '"Park, Hoon"'

31. Flexible Wing Kinematics of a Free-Flying Beetle (Rhinoceros Beetle Trypoxylus Dichotomus)

Author

Doyoung Byun, Tuyen Quang Le, Park Hoon, Min Jun Kim, and Tien Van Truong

Subjects
Wing, Angle of attack, business.industry, Biophysics, Bioengineering, Geometry, Rhinoceros, Kinematics, Wing twist, Camber (aerodynamics), Flapping, Aerospace engineering, business, Trypoxylus dichotomus, Geology, Biotechnology
Abstract

Detailed 3-Dimensional (3D) wing kinematics was experimentally presented in free flight of a beetle, Trypoxylus dichotomus, which has a pair of elytra (forewings) and flexible hind wings. The kinematic parameters such as the wing tip trajectory, angle of attack and camber deformation were obtained from a 3D reconstruction technique that involves the use of two synchronized high-speed cameras to digitize various points marked on the wings. Our data showed outstanding characteristics of deformation and flexibility of the beetle’s hind wing compared with other measured insects, especially in the chordwise and spanwise directions during flapping motion. The hind wing produced 16% maximum positive camber deformation during the downstroke. It also experienced twisted shape showing large variation of the angle of attack from the root to the tip during the upstroke.

Published
2012

32. Effect of chord flexure on aerodynamic performance of a flapping wing

Author

Doyoung Byun, Park Hoon, Soo Hyung Park, Jin Hwan Ko, and Tuyen Quang Le

Subjects
Physics, Airfoil, Chord (aeronautics), Reduced frequency, Wing, business.industry, Biophysics, Bioengineering, Thrust, Structural engineering, Aerodynamics, Finite element method, Physics::Fluid Dynamics, business, Propulsive efficiency, Biotechnology
Abstract

Inspired by the fact that a high flexible wing in nature generates high aerodynamic performance, we investigated the aerodynamic performance of the flapping wing with different chord flexures. The unsteady, incompressible, and viscous flow over airfoil NACA0012 in a plunge motion was analyzed by using Navier-Stokes equation. Grid deformation, in which finite element and interpolation ideas are mixed, was introduced for computing large grid deformation caused by the chord flexures. We explored the optimal phase angle for thrust force and propulsive efficiency by varying the chord flexure from 0.05 to 0.7 when reduced frequency and plunge amplitude were fixed. Throughout parametric study on the phase angle and chord flexure amplitude, the maximum thrust force is achieved near at 0° in all given conditions, meanwhile, it is found that the optimal phase angle has dependency of chord flexure amplitude, which achieves higher aerodynamic performance compared to previous studies. These findings will provide a useful guideline for determining wing flexibility in design of a bio-mimetic air vehicle.

Published
2010

38. Structural Characteristics of Allomyrina DichotomaBeetle’s Hind Wings for Flapping Wing Micro Air Vehicle

Author

Ha, Ngoc, Truong, Quang, Phan, Hoang, Goo, Nam, and Park, Hoon

Abstract

In this study, we present a complete structural analysis of Allomyrina dichotomabeetle’s hind wings by investigating their static and dynamic characteristics. The wing was subjected to the static loading to determine its overall flexural stiffness. Dynamic characteristics such as natural frequency, mode shape, and damping ratio of vibration modes in the operating frequency range were determined using a Bruel & Kjaer fast Fourier transform analyzer along with a laser sensor. The static and dynamic characteristics of natural Allomyrina dichotomabeetle’s hind wings were compared to those of a fabricated artificial wing. The results indicate that natural frequencies of the natural wing were significantly correlated to the wing surface area density that was defined as the wing mass divided by the hind wing surface area. Moreover, the bending behaviors of the natural wing and artificial wing were similar to that of a cantilever beam. Furthermore, the flexural stiffness of the artificial wing was a little higher than that of the natural one whereas the natural frequency of the natural wing was close to that of the artificial wing. These results provide important information for the biomimetic design of insect-scale artificial wings, with which highly maneuverable and efficient micro air vehicles can be designed.

Published
2014
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results