3D Unsteady Computations of Flapping Flight in Insects and Fish

Introduction: The flight of insects and birds and the swimming of fish have been sources of continuous fascination throughout the ages. Observation and controlled experimentation have historically been the main sources of information on performance. The mathematical description of the performance of flying creatures has been limited, due to the previously insurmountable difficulties associated with describing flapping wings with changing shape. Typical analytical descriptions are generally for steady flight only. Recent computational technology developments have enabled three-dimensional unsteady computations1,2 to be successfully completed for flapping wings and deforming shapes. 3D unsteady computations, coupled with appropriate experiments, can now provide a more complete view of the fluid dynamics underlying the remarkable aerodynamic and hydrodynamic feats observed in insects, birds, and fish. If we seek to attain that level of performance in our designed vehicles, we still have much to learn. This paper briefly summarizes some attempts we have made at the Naval Research Laboratory (NRL) to gain insights into the unsteady aerodynamic performance of flying insects and swimming fish, and to incorporate that understanding into the design of unmanned underwater vehicles and unmanned air vehicles.