Modelling the undulation patterns of flying snakes

Some species of snakes are good gliders and can travel as far as 330 feet from a height of 15m through air at speeds of around 9-12m/s. They possess a unique and complex aerial locomotion compared to other species of gliders. During glide, the snake morphs its transverse body section into an airfoil-like shape. In addition, it undulates its body in a characteristic fashion. Understanding the change in shape of flying snake due to this undulation is vital for gliding and maneuvering during glide. Previous studies have explained the effects of 2-D shape. Earlier computational studies on a fixed 3-D wing inspired by the snakes have revealed favorable aerodynamic characteristics. In the current work undulation patterns of a representative snake geometry is modelled mathematically and numerically. The generated shape exhibits lot of similarity to experimentally observed ones. By adding the cross-section of the snake to this shape, the 3-D snake geometry at different instances of time during undulation can be generated. Three dimensional CFD study using ANSYS is performed on these shapes assuming quasi-steady flow. The computed average glide angle agrees well with experimental data. This shows promise for the undulatory model proposed. The current work throws a better understanding of the undulatory motion and may lead to advances in the development of unconventional Micro-Air Vehicles and Snake-Bots apart from biomimetics.