The aerodynamics of flying snake airfoils in tandem configuration

ABSTRACT Flying snakes flatten their body to form a roughly triangular cross-sectional shape, enabling lift production and horizontal acceleration. While gliding, they also assume an S-shaped posture, which could promote aerodynamic interactions between the fore aft body. Such have been studied experimentally; however, very coarse models of snake's shape were used, effects measured only for downstream model. In this study, resulting from posture approximated using two-dimensional anatomically accurate airfoils positioned in tandem mimic geometry during flight. Load cells used measure drag forces, flow field data obtained digital particle image velocimetry (DPIV). The results showed strong dependence performance on arrangement, with coefficients being generally more influenced than coefficients. Flow revealed that arrangement modified separated wake size, enhanced cases vortices formed closer models, producing suction dorsal surface. downforce created by separation ventral surface at 0 deg angle attack was another significant factor contributing production. A number showing large variations included configurations close most probable airborne flying snakes, suggesting small postural be control glide trajectory.