Prediction of Delta Wing Leading-Edge Vortex Circulation and Lift-Curve Slope

1997 ◽  
Vol 34 (3) ◽  
pp. 450-452 ◽  
Author(s):  
Lance W. Traub
Keyword(s):  
Delta Wing ◽  
Leading Edge ◽  
Leading Edge Vortex ◽  
Lift Curve ◽  
Edge Vortex

Parametric Investigations of the Leading Edge Vortex on a Delta Wing

2011 ◽  
Author(s):  
Christoph Strangfeld ◽  
Lutz Taubert ◽  
C. Nayeri ◽  
Christian Paschereit
Keyword(s):  
Delta Wing ◽  
Leading Edge ◽  
Leading Edge Vortex ◽  
Edge Vortex

Leading-edge vortex behavior in the vicinity of delta wing apex

1996 ◽  
Author(s):  
Gregory Addington ◽  
Ernest Hanff ◽  
Robert Nelson
Keyword(s):  
Delta Wing ◽  
Leading Edge ◽  
Leading Edge Vortex ◽  
Edge Vortex

scholarly journals Effects of the Propeller Advance Ratio on Delta Wing UAV Leading Edge Vortex

2019 ◽  
Vol 16 (3) ◽  
pp. 6958-6970 ◽  
Author(s):  
K. A. Kasim ◽  
P. Segard ◽  
S. Mat ◽  
S. Mansor ◽  
M. N. Dahalan ◽  
...  
Keyword(s):  
Swirling Flow ◽  
Delta Wing ◽  
Active Flow Control ◽  
Pressure Coefficient ◽  
Leading Edge ◽  
Adverse Pressure Gradient ◽  
Leading Edge Vortex ◽  
Wing Model ◽  
Edge Vortex ◽  
Advance Ratio

Delta wing is a triangular-shaped platform that can be applied into the unmanned aerial vehicle (UAV) or drone applications. However, the flow above the delta wing is governed by complex leading-edge vortex structures which result in complicated aerodynamics behaviour. At higher angles of attack, the vortex burst can take place when the swirling flow is unable to sustain the adverse pressure gradient. More studies are needed to understand these vortex phenomena. This paper addresses an experimental study of active flow control called propeller on a generic 55° swept angle sharp-edged delta wing model. In this experiment, a propeller was placed at two different locations. The first location was at the apex of the wing while the second position was at the rear of the wing. The experiments were conducted in a 1.5 × 2.0 m2 closed-loop wind tunnel facility at Universiti Teknologi Malaysia. The freestream velocities were set at 20 m/s and 25 m/s. The research consisted of an intensive surface pressure measurement above the wing surface to investigate the effects of rotating propeller towards the leading-edge vortex. The experiments were divided into four configurations. The clean wing configuration was performed without the propeller and followed by pusher-propeller configuration using 10-inch 9-inch propellers. The final configuration was the tractor-propeller with a 10-inch propeller. The results emphasise the influences of the propeller size and its location corresponding to vortex properties above the delta-winged UAV model. The findings had indicated that the vortex peak is increased when the propeller is installed for both pusher and tractor configurations. The results also indicate that the pressure coefficient is increased when the propeller advance ratio increases. 

New Pair of Leading-Edge Vortex Structure for Flow over Delta Wing

2005 ◽  
Vol 42 (3) ◽  
pp. 718-721 ◽  
Author(s):  
Jinjun Wang ◽  
Jingxia Zhan
Keyword(s):  
Vortex Structure ◽  
Delta Wing ◽  
Leading Edge ◽  
Leading Edge Vortex ◽  
Edge Vortex

Characterization of a Three-Dimensional Leading-Edge Separation Bubble on Swept, Low Aspect-Ratio Propeller Blades

2017 ◽  
Author(s):  
Ye-Bonne Koyama Maldonado ◽  
Gregory Delattre ◽  
Cedric Illoul ◽  
Clement Dejeu ◽  
Laurent Jacquin
Keyword(s):  
Delta Wing ◽  
Separation Bubble ◽  
Three Dimensional ◽  
Leading Edge ◽  
Time Resolved ◽  
Leading Edge Vortex ◽  
Wall Structures ◽  
Edge Vortex ◽  
Propeller Blades ◽  
Leading Edge Vortices

Leading-edge vortex flows are often present on propeller blades at take-off, however, their characteristics and aerodynamic impact are still not fully understood. An experimental investigation using Time Resolved Particle Image Velocimetry (TR-PIV) has been performed on a model blade in order to classify this flow with respect to both delta wing leading-edge vortices and the low Reynolds number studies regarding leading-edge vortices on rotating blades. A numerical calculation of the experimental setup has been performed in order to assess usual numerical methods for propeller performance prediction against TR-PIV results. Similar characteristics were found with non slender delta wing vortices at low incidence, which hints that the leading-edge vortex flow may generate vortex lift. The influence of rotation on the characteristics of the leading-edge vortex is compared to that of the pressure gradient caused by the circulation distribution. A discussion on the quality of the PIV reconstruction for close-wall structures is provided.

Lift and the leading-edge vortex

2013 ◽  
Vol 720 ◽  
pp. 280-313 ◽  
Author(s):  
C. W. Pitt Ford ◽  
H. Babinsky
Keyword(s):  
Potential Flow ◽  
Flow Model ◽  
Order Approximation ◽  
Leading Edge ◽  
Kutta Condition ◽  
Leading Edge Vortex ◽  
Lift Curve ◽  
Edge Vortex ◽  
First Order Approximation ◽  
Potential Flow Model

AbstractFlapping wings often feature a leading-edge vortex (LEV) that is thought to enhance the lift generated by the wing. Here the lift on a wing featuring a leading-edge vortex is considered by performing experiments on a translating flat-plate aerofoil that is accelerated from rest in a water towing tank at a fixed angle of attack of 15°. The unsteady flow is investigated with dye flow visualization, particle image velocimetry (PIV) and force measurements. Leading- and trailing-edge vortex circulation and position are calculated directly from the velocity vectors obtained using PIV. In order to determine the most appropriate value of bound circulation, a two-dimensional potential flow model is employed and flow fields are calculated for a range of values of bound circulation. In this way, the value of bound circulation is selected to give the best fit between the experimental velocity field and the potential flow field. Early in the trajectory, the value of bound circulation calculated using this potential flow method is in accordance with Kelvin’s circulation theorem, but differs from the values predicted by Wagner’s growth of bound circulation and the Kutta condition. Later the Kutta condition is established but the bound circulation remains small; most of the circulation is contained instead in the LEVs. The growth of wake circulation can be approximated by Wagner’s circulation curve. Superimposing the non-circulatory lift, approximated from the potential flow model, and Wagner’s lift curve gives a first-order approximation of the measured lift. Lift is generated by inertial effects and the slow buildup of circulation, which is contained in shed vortices rather than bound circulation.

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