TY - GEN
T1 - Experimental study on flow interaction between fore- and hindwings of dragnofly in hovering and forward flight
AU - Nagai, Hiroto
AU - Isogai, Koji
AU - Fujimoto, Tatsumi
PY - 2010/12/1
Y1 - 2010/12/1
N2 - There are various flow interactions between the fore- and hindwings of a dragonfly. However, the detailed mechanism of flow interaction between the fore- and hindwings has not been well understood. In this study, we clarify the aerodynamic mechanisms of flow interaction between fore- and hindwings of a dragonfly in hovering and forward flights. Measurements of unsteady aerodynamic forces acting on the tandem wings are conducted using a dynamically scaled mechanical model in a water tunnel. Moreover, flow visualization around the tandem wings is conducted using Particle Image Velocimetry. The effect of the phase difference between the fore- and hindwings on the aerodynamic characteristics is investigated in hovering and forward flights. The results indicate that the advanced hindwing ahead of the forewing, which is often used in steady flights of dragonflies, has a smaller variation with respect to the phase difference and a smaller difference between the fore- and hindwings in hovering and forward flight. In hovering flight, the flow interaction reduces the aerodynamic characteristics except at the phase difference of 0 deg. In forward flight, the advanced hindwing generates larger lift with a good efficiency than that without interaction.
AB - There are various flow interactions between the fore- and hindwings of a dragonfly. However, the detailed mechanism of flow interaction between the fore- and hindwings has not been well understood. In this study, we clarify the aerodynamic mechanisms of flow interaction between fore- and hindwings of a dragonfly in hovering and forward flights. Measurements of unsteady aerodynamic forces acting on the tandem wings are conducted using a dynamically scaled mechanical model in a water tunnel. Moreover, flow visualization around the tandem wings is conducted using Particle Image Velocimetry. The effect of the phase difference between the fore- and hindwings on the aerodynamic characteristics is investigated in hovering and forward flights. The results indicate that the advanced hindwing ahead of the forewing, which is often used in steady flights of dragonflies, has a smaller variation with respect to the phase difference and a smaller difference between the fore- and hindwings in hovering and forward flight. In hovering flight, the flow interaction reduces the aerodynamic characteristics except at the phase difference of 0 deg. In forward flight, the advanced hindwing generates larger lift with a good efficiency than that without interaction.
UR - http://www.scopus.com/inward/record.url?scp=84878450545&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878450545&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84878450545
SN - 9781617820496
T3 - 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010
SP - 998
EP - 1007
BT - 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010
T2 - 27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010
Y2 - 19 September 2010 through 24 September 2010
ER -