Numerical analysis of biomimetic gannet impacting with water during plunge-diving

Abstract

This paper reproduces the plunge-diving process of a biomimetic gannet through the CFD (Computational Fluid Dynamics) simulation. The numerical investigation of impulse force and pressure distribution on the designed biomimetic gannet when interacting with water is also presented. Three-dimensional computational transport equations based on the complete set of Navier-Stokes equations are solved by using the FLUENT 6.2 solver. Numerical simulations have been performed to examine the flow characteristics on the interface between air and water, where the interface is tracked by coupling the VOF (Volumn of Fluid) method. The biomimetic gannet is developed by imitating the natural gannet, the morphology and water-entry posture of which are the same as those of the gannet in nature. For different given dropping heights, the effect of initial water-entry velocity on the axial impact force acting on the gannet's body is investigated and numerically examined.