Vortex Dynamics in Near Wake of a Hovering Hawkmoth
نویسندگان
چکیده
Numerical investigation of vortex dynamics in near wake of a hovering hawkmoth and hovering aerodynamics is conducted with a biology-inspired dynamic flight simulator. This simulator is developed to be capable of ‘flying’ an insect on a basis of realistic wing-body morphologies and kinematics. The computed results show a three-dimensional mechanism of vortical structures in hawkmoth hovering. A horseshoe-shaped vortex is observed, which wraps around each wing during the early downand upstroke but subsequently grows into a doughnutshaped vortex ring, with an intense jet-flow present in its core, forming the downwash. The doughnut-shaped vortex rings of the wing pair eventually break up into two circular vortex rings downward in the wake. We furthermore evaluate the hovering energetics in terms of torques and powers based on the computed aerodynamic forces and velocity of the flapping wings.
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