Vortex Structure around Heaving Elastic Airfoils and Characteristics of Dynamic Thrust

It is well known that insects and aquatic animals fly or swim by skillfully controlling wings that deform elastically and vortices generated around the body. A flow around an elastic body is treated as a coupled problem of a fluid and a structure and it has been studied mainly by numerical analyses so far. The authors measured vortex flow in the wake of the rigid flat plate, rigid NACA0010, elastic flat plate and elastic NACA0010 with heaving motions and evaluated accelerating flows induced by the vortex flow patterns and vortex flows in the wake of the airfoils. Furthermore, we measured dynamic thrusts acting on these airfoils with heaving motions and clarified their relations with vortex flows.

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