Hydrodynamic performance of an autonomous underwater glider with a pair of bioinspired hydro wings-A numerical investigation

A conceptual design of autonomous underwater glider (AUG) is introduced, with a pair of bio-inspired hydro wings undergoing travelling wave motion. Hydrodynamic performance of current AUG is investigated by numerically solving the incompressible viscous Navier-Stokes equations of its surrounding flow coupling with the immersed boundary method to capture the moving boundaries. The force balance along the stream direction is guaranteed by adjusting the kinematic parameters of the travelling wave motion, thus the cruise state of the AUG with a constant velocity can be achieved. The propulsive efficiency under cruise state is therefore directly and well defined. The effects of kinematic parameters on propulsive performance are investigated, and the non-dimensional Strouhal number, as a combination of these kinematic parameters, turns to be a dominant parameter of the propulsive efficiency. There is an optimum range of Strouhal number, in which the AUG achieves its maximum efficiency. The results obtained in current study can provide certain technical supports for the design and development of small submersible vehicle.