Numerical Simulation of the Streamwise Transport of a Delta Wing Leading-Edge Vortex

2021 ◽  
pp. 1-12
Author(s):  
Daniela G. François ◽  
Silvia Probst ◽  
Tobias Knopp ◽  
Cornelia Grabe ◽  
Tim Landa ◽  
...  
Author(s):  
Christoph Strangfeld ◽  
Lutz Taubert ◽  
C. Nayeri ◽  
Christian Paschereit

1996 ◽  
Author(s):  
Gregory Addington ◽  
Ernest Hanff ◽  
Robert Nelson

Author(s):  
K. A. Kasim ◽  
P. Segard ◽  
S. Mat ◽  
S. Mansor ◽  
M. N. Dahalan ◽  
...  

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. 


2005 ◽  
Vol 42 (3) ◽  
pp. 718-721 ◽  
Author(s):  
Jinjun Wang ◽  
Jingxia Zhan

2017 ◽  
Vol 835 ◽  
pp. 406-420 ◽  
Author(s):  
Injae Lee ◽  
Haecheon Choi

We provide a scaling law for the lift force of autorotating falling seeds at terminal velocity to describe the relation among the lift force, seed geometry and terminal descending and rotating velocities. Two theories, steady wing-vortex theory and actuator-disk theory, are examined to derive the scaling law. In the steady wing-vortex theory, the strength of a leading-edge vortex is scaled with the circulation around a wing and the lift force is modelled by the time derivative of vortical impulse, whereas the conservations of mass, linear and angular momentum, and kinetic energy across the autorotating falling seed are applied in the actuator-disk theory. To examine the validity of the theoretical results, an unsteady three-dimensional numerical simulation is conducted for flow around an autorotating seed (Acer palmatum) during free fall. The sectional lift coefficient predicted from the steady wing-vortex theory reasonably agrees with that from the numerical simulation, whereas the actuator-disk theory fails to provide an estimation of the sectional lift coefficient. The weights of 11 different species of autorotating falling seeds fall on the scaling law derived from the steady wing-vortex theory, suggesting that even a simple theoretical approach can explain how falling seeds support their weights by autorotation once the circulation from a leading-edge vortex is properly included in the theory.


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