Flapping Flight: High Thrust and Propulsive Efficiency due to Forward Gliding Oscillations

摘要

The aerodynamic effect of superimposed forward gliding oscillations parallel to the free stream velocity on a classical flapping motion (combined pitch/plunge motion) is investigated with unsteady Reynolds-averaged Navier-Stokes simulations and is compared with results of an inyiscid theory. It is shown that superimposed forward gliding motions during the flapping downstroke, which are observed on flapping birds in nature, increase both propulsive efficiency and thrust.