The flow field characters of a two-dimensional deformable wing heaving in a viscous flow

A systematic study for the flow around a deformable wing heaving in a prescribed motion at a Reynolds number of 10⁴ is carried out through the numerical solution of the two-dimensional unsteady incompressible Navier-Stokes equations. Special attention is paid to the effect of the frequencies and amplitudes of the flexure wing on the wake structure and vortex shedding mechanism. The effect of flexible features on the forward flight of the wing is discussed by comparing the flow structures with those around a rigid wing. The simulation results reveal that the thrust efficiency of the deformable wing is higher than the rigid wing. The efficiency is improved because of flexure and is predominantly influenced by the reduced frequency.