Numerical study on aerodynamic performance of flapping wings

A numerical study on the aerodynamic performance of an unsteady flapping motion generated by a simplified model of a dragonfly's wing(2D) has been carried out using the finite volume method.The effects of the wing thickness,the frequency and the amplitude of the flapping motion have been examined.It is found that as the wing thickness increases the lift and thrust forces decrease,while as the amplitude of the flapping motion increases the forces increase remarkably.As the flapping frequency varies from 10 to 160Hz,both the lift and thrust forces increase sharply first and then experience a peak in 30-50Hz before decreasing slowly.In a flapping period,the downstroke mainly generates the lift force while the upstroke generates the thrust.