Computer programs have been written to evaluate the integrals of lifting-surface theory for the velocity field of a thin wing with given load distribution. Different programs are used for the downwash at points on the wing, and for any or all three velocity components off the wing. The heart of the programs is an analytic evaluation of the spanwise integral over a short line following the local...

The relationship between lateral static stability derivative, Clβ , lift coefficient, CL, and angle of attack was investigated for rectangular wings of aspect ratioA= 0.75,1,1.5, and 3 using Stereo-Digital Particle Image Velocimetry (S-DPIV) and direct force and moment measurements. When the product ClβA is plotted with respect to CL, the lateral stability curves of each wing collapse to a sing...

While biological flyers often display deformed wing structures, the effects of flexibility on the flapping wing aerodynamics remain inadequately understood. We investigate the lift generation and phase dynamics of a flapping flexible wing in hover, between Reynolds number of 100 and 1000 corresponding to small insects, using fully coupled Navier-Stokes equation and linear beam model. The γ scal...

We investigate initiation, growth, and healing of wing cracks in confined silica glass by molecular dynamics simulations. Under dynamic compression, frictional sliding of precrack surfaces nucleates nanovoids which evolve into nanocrack columns at the precrack tip. Nanocrack columns merge to form a wing crack, which grows via coalescence with nanovoids in the direction of maximum compression. L...

During flight, the wings of many insects undergo considerable shape changes in spanwise and chordwise directions. We determined the origin of spanwise wing deformation by combining measurements on segmental wing stiffness of the blowfly Calliphora vicina in the ventral and dorsal directions with numerical modelling of instantaneous aerodynamic and inertial forces within the stroke cycle using a...

This study investigates the unsteady flow phenomena generated from plunging wings with varying flexibility. The experiments were conducted in a wind tunnel with forward flight conditions at a chord based Reynolds number of 5300. The wings are fabricated out of homogeneous isotropic materials with values of 55 and 1702. The conditions of these experiments are matched to previous studies in a wat...

During the moult, birds sequentially replace their flight feathers and thus temporarily have gaps in their wings. These gaps will vary in size and position(s) during the course of the moult. We investigated the aerodynamic effects of having moult gaps in a rectangular wing by using a vortex-lattice (panel) approach, and we modelled the effect of moult gap size at the wing moult initiation posit...

An experimental investigation is conducted to study the effect of multiscale endplates on wing-tip vortex and wing aerodynamic performance at Reynolds numbers 215,000 244,000 based mean chord a NACA 0012 half-span wing. Two groups are tested. The first group has three different fractal patterns applied along top edge endplate, while second two-scale its outboard surface. It experimentally shown...

The flow over a flat-tipped wing at three Reynolds numbers: R e = 1 × 10 4 , 4, and 5 is investigated using direct numerical simulation. A set of grid independent results are obtained which allow for the dynamics tip flow, trailing vortices, their interplay with boundary layer to be examined in detail. show significant changes across number range. At lowest number, single vortex forms downstrea...