On the Unsteady Aerodynamics and Design of Flapping Wing Vehicles

Flying birds, bats and insects have always inspired humans to venture into developing bio-inspired flying machines. Such vehicles imitate flapping wing concept are also known as Ornithopters. Efforts to build such vehicles date back to 9th-century work by famous Arab scientist Abbas-Ibn-Firnas. Despite many efforts, design and development of such vehicle remained a challenge. The major limitation in this regard is the limited knowledge of related aerodynamic concepts like, Low-Reynolds number phenomenon, vortex induced lift, non-linear fluid structure interaction, high flapping frequency, low weight, complex mechanics, stabilization and controls algorithms. This review paper is aimed to provide an insight into recent developments in understanding the complex dynamics of flapping wing vehicles. Notable experimental works and numerical investigations have been discussed in details; special emphasis has been laid on computational techniques for analysing complex dynamics and design of flapping wing vehicles. Moreover, the modern trends in design, power requirement, motion control and mathematical modelling are also explored.