Abstract: The propulsive performance of a tandem wing system that has a stationary trailing wing and a flapping leading wing was calculated. The viscous incompressible NavierStokes equations were solved by the finite volume method in conjunction with the Standard kε turbulence model. The sliding mesh method was adopted to achieve the relative motion between the leading wing and the trailing wing. The relationships between the reduced frequencies, flapping amplitude, and trailing distance with propulsive performance were investigated. The results show that the propulsive efficiency of tandem wing system is higher than single flapping wing in an appropriate reduced frequency and flapping amplitude region, and most of the thrust is produced by leading wing, the propulsive performance is minimal dependent on trailing distance.

Key words:  tandem wing, propulsive efficiency, sliding mesh, flapping wing