TY - JOUR
T1 - Effect of flexion on the propulsive performance of a flexible flapping wing
AU - Deng, Shuanghou
AU - Xiao, Tianhang
PY - 2016/10/1
Y1 - 2016/10/1
N2 - A numerical study was carried out to investigate the effect of chordwise flexion on the propulsive performance of a two-dimensional flexible flapping wing. The wing undergoes a prescribed sinusoidal heaving motion with a local deflection. A deformable overset grid dynamic mesh method was employed to implement the motion of the grid instantaneously. The effect of flexural pattern, flexural amplitude and flapping frequency in terms of Strouhal number are evaluated. Unsteady flow around the wing is computed using an in-house developed Unsteady Reynolds-Averaged Navier-Stokes (URANS) solver. The results show that the different flexural patterns will create different flow fields, and thus the thrust generation will be significantly varied. The thrust and propulsive efficiency do not increase monotonically with the flexure amplitude while a peak value is revealed. It is found that the wake vortices after the flapping motion assembly behave as a reverse von-Karman vortex street, which can principally create thrust. The thrust is found to increase with increasing Strouhal number. Propulsive efficiency is beneficial from the chordwise flexibility and peaks within the range of 0.2 <St <0.4, which is evidenced by natural flyers.
AB - A numerical study was carried out to investigate the effect of chordwise flexion on the propulsive performance of a two-dimensional flexible flapping wing. The wing undergoes a prescribed sinusoidal heaving motion with a local deflection. A deformable overset grid dynamic mesh method was employed to implement the motion of the grid instantaneously. The effect of flexural pattern, flexural amplitude and flapping frequency in terms of Strouhal number are evaluated. Unsteady flow around the wing is computed using an in-house developed Unsteady Reynolds-Averaged Navier-Stokes (URANS) solver. The results show that the different flexural patterns will create different flow fields, and thus the thrust generation will be significantly varied. The thrust and propulsive efficiency do not increase monotonically with the flexure amplitude while a peak value is revealed. It is found that the wake vortices after the flapping motion assembly behave as a reverse von-Karman vortex street, which can principally create thrust. The thrust is found to increase with increasing Strouhal number. Propulsive efficiency is beneficial from the chordwise flexibility and peaks within the range of 0.2 <St <0.4, which is evidenced by natural flyers.
KW - dynamic mesh
KW - flapping wing
KW - flexion
KW - Numerical simulation
KW - propulsive performance
UR - http://www.scopus.com/inward/record.url?scp=84986277908&partnerID=8YFLogxK
U2 - 10.1177/0954410015623304
DO - 10.1177/0954410015623304
M3 - Article
AN - SCOPUS:84986277908
VL - 230
SP - 2265
EP - 2273
JO - Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering
JF - Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering
SN - 0954-4100
IS - 12
ER -