scholarly journals Effect of wing mass in free flight of a two-dimensional symmetric flapping wing–body model

2017 ◽  
Vol 49 (5) ◽  
pp. 055504
Author(s):  
Kosuke Suzuki ◽  
Takaaki Aoki ◽  
Masato Yoshino
Keyword(s):  
Flapping Wing ◽  
Two Dimensional ◽  
Free Flight ◽  
Body Model

1603 Effect of Wing Mass in Free Flight of a Two Dimensional Symmetric Flapping Wing

2016 ◽  
Vol 2016.53 (0) ◽  
pp. _1603-1_-_1603-5_
Author(s):  
Takaaki AOKI ◽  
Kosuke SUZUKI ◽  
Masato YOSHINO
Keyword(s):  
Flapping Wing ◽  
Two Dimensional ◽  
Free Flight

Sudden Loading During a Dynamic Lifting Task: A Simulation Study

2005 ◽  
Vol 127 (1) ◽  
pp. 108-113 ◽  
Author(s):  
T. Bull Andersen ◽  
E. B. Simonsen
Keyword(s):  
Factor Loading ◽  
Whole Body ◽  
Forward Dynamics ◽  
Two Dimensional ◽  
Body Model ◽  
Nursing Aide ◽  
Initial Load ◽  
Sudden Loading ◽  
Dynamics Simulations ◽  
Lifting Task

It is believed that nurses risk the development of back pain as a consequence of sudden loadings during tasks in which they are handling patients. Forward dynamics simulations of sudden loads (applied to the arms) during dynamic lifting tasks were performed on a two-dimensional whole-body model. Loads were in the range of −80kg to 80 kg, with the initial load being 20 kg. Loading the arm downwards with less than that which equals a mass of 20 kg did not change the compressive forces on the spine when compared to a normal lifting motion with a 20 kg mass in the hands. However, when larger loads (40 kg to 80 kg extra in the hands) were simulated, the compressive forces exceeded 13 000 N (above 3 400 N is generally considered a risk factor). Loading upwards led to a decrease in the compressive forces but to a larger backwards velocity at the end of the movement. In the present study, it was possible to simulate a fast lifting motion. The results showed that when loading the arms downwards with a force that equals 40 kg or more, the spine was severely compressed. When loading in the opposite direction (unloading), the spine was not compressed more than during a normal lifting motion. In practical terms, this indicates that if a nursing aide tries to catch a patient who is falling, large compressive forces are applied to the spine.

scholarly journals Effect of simplifying the body model to compute the energy parameters in pole vaulting

2019 ◽  
Author(s):  
Julien Frère ◽  
Hervé Sanchez ◽  
Romain Vanhaesebrouck ◽  
Johan Cassirame
Keyword(s):  
Mechanical Energy ◽  
The Body ◽  
Two Dimensional ◽  
Energy Parameters ◽  
Time Profiles ◽  
Body Model ◽  
Good Compromise ◽  
Three Body

This study compared changes in the energy time-profiles and related parameters in pole vaulting using three body models. Two-dimensional kinematics were collected from 20 trials (5.20-6.01 m) performed by 10 athletes during a competition. The linear and angular kinetic, potential, and mechanical energy time-profiles were obtained from three pole vaulter models composed of 12, 5, and 3 segments (M12, M5, and M3, respectively). The energy values of M5, compared to those of M3, were more similar to M12 and appeared to be a good compromise between the decreased number of digitized points and the reliability of the energetic outcomes in pole vaulting.

scholarly journals Effect of Wing Corrugation on the Aerodynamic Efficiency of Two-Dimensional Flapping Wings

2020 ◽  
Vol 10 (20) ◽  
pp. 7375
Author(s):  
Thanh Tien Dao ◽  
Thi Kim Loan Au ◽  
Soo Hyung Park ◽  
Hoon Cheol Park
Keyword(s):  
Three Dimensional ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Two Dimensional ◽  
Aerodynamic Efficiency ◽  
Insect Wing ◽  
Wing Motion ◽  
Computational Fluid Dynamics Cfd

Many previous studies have shown that wing corrugation of an insect wing is only structurally beneficial in enhancing the wing’s bending stiffness and does not much help to improve the aerodynamic performance of flapping wings. This study uses two-dimensional computational fluid dynamics (CFD) in aiming to identify a proper wing corrugation that can enhance the aerodynamic performance of the KUBeetle, an insect-like flapping-wing micro air vehicle (MAV), which operates at a Reynolds number of less than 13,000. For this purpose, various two-dimensional corrugated wings were numerically investigated. The two-dimensional flapping wing motion was extracted from the measured three-dimensional wing kinematics of the KUBeetle at spanwise locations of r = (0.375 and 0.75)R. The CFD analysis showed that at both spanwise locations, the corrugations placed over the entire wing were not beneficial for improving aerodynamic efficiency. However, for the two-dimensional flapping wing at the spanwise location of r = 0.375R, where the wing experiences relatively high angles of attack, three specially designed wings with leading-edge corrugation showed higher aerodynamic performance than that of the non-corrugated smooth wing. The improvement is closely related to the flow patterns formed around the wings. Therefore, the proposed leading-edge corrugation is suggested for the inboard wing of the KUBeetle to enhance aerodynamic performance. The corrugation in the inboard wing may also be structurally beneficial.

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