Effects of the Rotation Phase on the Average Lift of an Insect-Like Flapping Wing ☆

Insect-like flapping wings are characterized by multi-degree-of-freedom motions at the wing base, which can be divided into two main movements: sweep and rotation. The phase difference between sweep and rotation motions is an important kinematic parameter that has a great influence on the wing lift. In this paper, the effect of the rotation phase on the average lift of a hawkmoth-like wing is investigated. Simulations were conducted using a Fluid-Structure Interaction co-simulation framework developed based on the multibody dynamics approach and an unsteady vortex-lattice method. The results show that maximum lift for the rigid wing is reached at an advanced phase of about 10%. For the flexible wing, maximum lift is reached at a delayed phase of about 5%. The reason for this difference could be the passive deformation of the flexible wing, which causes an advanced rotation phase at the wing tip. The obtained results are in good agreement with experimental results conducted by previous studies.