Control of Leading Edge Vortices Using Apex Flap over Non-Slender Delta Wing

2013 ◽  
Vol 390 ◽  
pp. 12-17
Author(s):  
Hafiz Laiq-Ur Rehman
Keyword(s):  
Vortex Flow ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Leading Edge ◽  
Pressure Probe ◽  
Sweep Angle ◽  
Strong Shear ◽  
Flap Deflection ◽  
Probe Measurements ◽  
Leading Edge Vortices

This manuscript presents the vortex flow structure over non-slender delta wing with leading edge sweep angle, Λ=45°. A comprehensive investigation has been conducted in wind tunnel at Reynolds number ranging from, Re = 247,000 - 445,000. Seven-hole pressure probe measurements for axial vorticity, axial velocity, vortex trajectory and pressure variations are presented at various chordwise stations and angles of incidences. It was demonstrated that weak leading edge vortices are generated very close to the wing surface with strong shear layer which move upward and outboard with apex flap deflection. Reattachment line move towards wing root chord with the increase in angle of attack. Passive apex flap has been used to control the leading edge vortices and to delay the vortex breakdown. It is recognized that vortex breakdown was delayed by 8% by downward apex flap deflection.

Unsteady Characteristics of Breakdown Vortices over Delta Wing

2011 ◽  
Vol 66-68 ◽  
pp. 1874-1877 ◽  
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Zhi Yong Lu ◽  
Li Lu
Keyword(s):  
Wind Tunnel ◽  
Vortex Flow ◽  
Vortex Breakdown ◽  
Delta Wing ◽  
Pressure Fluctuations ◽  
Spiral Wave ◽  
Leading Edge ◽  
Fluid State ◽  
Unsteady Characteristics ◽  
Leading Edge Vortices

Experiment of unsteady pressure measurement on the surface of wing with 75° sweep delta wing has been carried out in a wind tunnel in order to investigate unsteady characteristics of breakdown vortices over delta wing after the leading edge vortices were breakdown. The result of experiment shows that alter of RMS pressure fluctuations and fluid state of leading edge vortices on the top surface of delta wing are correlative. At the angle region with vortex breakdown, RMS of pressure fluctuations are very huge, similarly buffeting strength of delta wing are large. With increasing angle of attack, alter of buffeting strength is in accordance with RMS pressure fluctuations. Analysis of the pressure signal shows the spiral wave of the breakdown vortex flow over the wing is the primary part of whole RMS pressure fluctuations. Delta wing produces buffeting because of the spiral wave.

Experimental Control of Vortex Breakdown by Pulsed Blowing Over a Delta Wing With Rounded Leading-Edge

2002 ◽  
Author(s):  
Renac Florent ◽  
Molton Pascal ◽  
Barberis Didier
Keyword(s):  
Vortex Breakdown ◽  
Delta Wing ◽  
Laser Sheet ◽  
Leading Edge ◽  
Control Device ◽  
Surface Flow ◽  
Sweep Angle ◽  
Laminar To Turbulent Transition ◽  
Pressure Distributions ◽  
Oil Flow

The purpose of this study is to construct and test an experimental device to control vortex on a delta wing. The model has a root chord of c = 690mm and a sweep angle of Λ = 60°. The control system is based on four rectangular slits 50 mm long and 0.2 mm wide running along the leading edge. This configuration produces jets normal to the leading edge. The mass flow rates and frequencies of injection can be varied independently. The results are shown in the form of surface flow visualizations, with the skin friction pattern exhibited by oil flow visualization, and the laminar-to-turbulent transition by acenaphthene. Mean and instantaneous surface pressure distributions were determined with Kulite™ sensors and the velocity field was determined by 3D laser Doppler velocimetry (LDV) measurements. Control device efficiencies were evaluated by laser sheet visualization.

Aerodynamics and Vortex Flowfield of a Slender Delta Wing With Apex Flap and Tip Flap

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
T. Lee ◽  
L. S. Ko
Keyword(s):  
Vortex Flow ◽  
Opposite Effect ◽  
Particle Image ◽  
Delta Wing ◽  
Leading Edge ◽  
Piv Measurements ◽  
Injection Flow ◽  
Image Velocimetry ◽  
Edge Vortex ◽  
Flap Deflection

The effect of apex flap and tip flap, deflected both independently and jointly, on the vortex flow and lift generation of a 65 deg-sweep delta wing was investigated experimentally. The drooped apex flap produced a higher lift at medium-to-high angle of attack regime and also a delayed stall. The anhedral (introduced by the downward tip flap) generally promoted lift increment, whereas dihedral had the opposite effect. Meanwhile, the joint apex and tip flap deflection gave a delayed leading-edge vortex (LEV) breakdown and an enhanced lift. The LEVs were generally drawn closer to the wing upper surface, while being pushed further away from the wing centerline by the application of apex flap and tip flap. The flap also modified the vorticity distribution in the LEV; the bursting behavior was, however, not affected. Dye-injection flow visualization and particle image velocimetry (PIV) measurements of the vortex flow were also discussed.

The effect of a 70 deg swept canard on the leading-edge vortices of a 70 deg swept delta wing during dynamic pitching

1997 ◽  
Author(s):  
Shigeo Hayashibara ◽  
Roy Myose ◽  
L. Miller ◽  
Shigeo Hayashibara ◽  
Roy Myose ◽  
...  
Keyword(s):  
Delta Wing ◽  
Leading Edge ◽  
Leading Edge Vortices

On the Breakdown at High Incidences of the Leading Edge Vortices on Delta Wings

1960 ◽  
Vol 64 (596) ◽  
pp. 491-493 ◽  
Author(s):  
B. J. Elle
Keyword(s):  
High Speed ◽  
Recent Article ◽  
Vortex Breakdown ◽  
Leading Edge ◽  
Critical Value ◽  
Delta Wings ◽  
Edge Separation ◽  
Leading Edge Vortices

In a recent article, H. Werlé, has described how the free spiral vortices on delta wings with leading edge separation suddenly expand if the incidence is increased beyond a critical value. His description conforms to a great extent with the results, arrived at during an English investigation of the same phenomenon (called the vortex breakdown), but the interpretations of the observations, suggested by the two sources, are different. Against this background it is felt that some further comments and some pertinent high speed observations, may be of interest.

Optimization of Aerodynamic Parameters of Cropped Delta Wing with Fence at Sonic Mach Number

2019 ◽  
Vol 16 (2) ◽  
pp. 403-409
Author(s):  
M. P. Arun ◽  
M. Satheesh ◽  
Edwin Raja J. Dhas
Keyword(s):  
Shock Wave ◽  
Boundary Condition ◽  
Mach Number ◽  
Sound Speed ◽  
Delta Wing ◽  
Leading Edge ◽  
Supersonic Speed ◽  
Sweep Angle ◽  
Ansys Fluent ◽  
Aerodynamic Parameters

Manufacturing and maintaining different aircraft fleet leads to various purposes, which consumes more money as well as man power. Solution to this, nations that are leading in the field of aeronautics are performing much research and development works on new aircraft designs that could do the operations those were done by varied aircrafts. The foremost benefit of this delta wing is, along the huge rearward sweep angle, the wing’s leading edge would not contact the boundary of shock wave. Further, the boundary is produced at the fuselage nose due to the speed of aircraft approaches and also goes beyond the transonic to supersonic speed. Further, rearward sweep angle greatly worse the airspeed: wings under normal condition to leading edge, so permits the aircraft to fly at great transonic, subsonic, or supersonic speed, whereas the over wing speed is kept to minimal range than that of the sound speed. The cropped delta wing with fence has analysed in three cases: Fences at 3/4th distance from the centre, with fences at half distance from the centre and with fences at the centre. Further, the delta wing that cropped is exported to ANSYS FLUENT V14.0 software and analysed by making the boundary condition settings like sonic Mach number of flow over wing along with the angle of attack.

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