Large ears enhance perception of echolocation and prey generated sounds in bats. However, external ears likely impair aerodynamic performance of bats compared to birds. But large ears may generate lift on their own, mitigating the negative effects. We studied flying brown long-eared bats, using high resolution, time resolved particle image velocimetry, to determine the aerodynamics of flying wi...

During slow flight, bird species vary in their upstroke kinematics using either a 'flexed wing' or a distally supinated 'tip-reversal' upstroke. Two hypotheses have been presented concerning the function of the tip-reversal upstroke. The first is that this behavior is aerodynamically inactive and serves to minimize drag. The second is that the tip-reversal upstroke is capable of producing signi...

Detailed 3-Dimensional (3D) wing kinematics was experimentally presented in free flight of a beetle, Trypoxylus dichotomus, which has a pair of elytra (forewings) and flexible hind wings. The kinematic parameters such as the wing tip trajectory, angle of attack and camber deformation were obtained from a 3D reconstruction technique that involves the use of two synchronized high-speed cameras to...

Many flying animals use both flapping and gliding flight as part of their routine behaviour. These two kinematic patterns impose conflicting requirements on wing design for aerodynamic efficiency and, in the absence of extreme morphing, wings cannot be optimised for both flight modes. In gliding flight, the wing experiences uniform incident flow and the optimal shape is a high aspect ratio wing...

Nomenclature L y spanwise coordinate q net beam loading S shear M bending moment θ deflection angle (= dw/dx) w deflection κ local beam curvature ′ lift/span distribution ′ S η normalized spanwise coordinate (= 2y/b) c local wing chord wing wing area b wing span λ taper ratio E Young's modulus δ tip deflection N load factor m wing mass/span distribution I bending inertia i spanwise station inde...

Large eddy simulation with filtered-structure-function subgrid model and implicit large eddy simulation (ILES without explicit subgrid model) using high-order accuracy and high resolution compact scheme have been performed on the tip vortex shedding from a rectangular half-wing with a NACA 0012 airfoil section and a rounded wing tip. The formation of the tip vortex and its initial development i...

The influences of the leader in a group of V – flight formation are dealt with. The investigation is focused on the effect of its position and shape on aerodynamics performances of a given V – flight formation. Vortices generated the wing tip of the leader moves downstream forming a pair of opposite rotating line vortices. These vortices are generally undesirable because they create a downwash ...

The aileron is one of the most important tools for adjusting roll attitude aircraft, but surface flow state likely to be affected by high-lift devices. In this paper, using computational fluid dynamics (CFD) simulations and wind tunnel tests, Krueger flap effects on ailerons in a typical blended wing body civil aircraft were investigated. order increase lift, deflecting makes separation occur B...