Vortex sheets rolling-up along leading-edges of delta wings

1966 ◽  
Vol 7 ◽  
pp. 7-33 ◽  
Author(s):  
Robert Legendre
Keyword(s):  
Delta Wings ◽  
Vortex Sheets ◽  
Leading Edges

Vortex Breakdown Effects on the Low-speed Aerodynamic Characteristics of Slender Delta Wings in Symmetrical Flow

1967 ◽  
Vol 71 (676) ◽  
pp. 319-322 ◽  
Author(s):  
D. Hummel ◽  
P. S. Srinivasan
Keyword(s):  
Vortex Breakdown ◽  
Vortex Formation ◽  
Vortex Sheet ◽  
Aerodynamic Characteristics ◽  
Flow Visualisation ◽  
Delta Wings ◽  
Vortex Sheets ◽  
The Core ◽  
Leading Edges ◽  
Slender Wing

Even at small angles of incidence, the flow separates from the sharp leading edges of a slender wing. These flow separations usually lead to the formation of two free vortex layers, joined to the leading edges of the wing and rolling up to form spiral-shaped vortex sheets above the upper surface of the wing. This vortex formation is illustrated schematically in Fig. 1. The streamlines on the vortex sheet follow helical paths. Smoke injected near the wing apex for flow visualisation remains concentrated close to the axis of the core of the vortex sheet.

From Ship-Accompanying Waves to Shock Waves of Supersonic Aeroplanes

1962 ◽  
Vol 66 (615) ◽  
pp. 163-176
Author(s):  
Robert G. Legendre
Keyword(s):  
Shock Waves ◽  
Delta Wing ◽  
Good Reason ◽  
Point Of View ◽  
Memorial Lecture ◽  
Vortex Sheets ◽  
Leading Edges

When I was invited to deliver the Lanchester Memorial lecture, I wondered why the great honour of being the first Frenchman selected for the celebration of the deeds of a great engineer was conferred on me. However, I am well aware that the Council of the Royal Aeronautical Society cannot make a mistake and there is good reason to choose, after so greatly famed professors, an engineer of the French Navy to illustrate, using a slightly different point of view, the influence of Lanchester on the development of aeronautics. This way, I do not have to apologise for a possible inadequacy which then would not be my own responsibility. I have only to do my best, so as not to betray the confidence of the Society. Answering so plainly this first question, I had to find out how to fulfil my task. Possibly, my contribution to the intrepretation of the vortex sheets starting from the thin leading edges of a delta wing is more in the Lanchester line of thought than it is an extension of Prandtl’s inferences.

scholarly journals The Effects of Blunt Leading Edges on Delta Wings at Mach 5.8

1958 ◽  
Vol 25 (12) ◽  
pp. 786-787
Author(s):  
Kenneth F. Nicholson
Keyword(s):  
Delta Wings ◽  
Leading Edges

scholarly journals Analysis of Damping Derivatives for Delta Wings in Hypersonic Flow for Curved Leading Edges with Full Sine Wave

2019 ◽  
Vol 9 (1) ◽  
pp. 5457-5466
Keyword(s):  
Deflection Angle ◽  
Center Of Pressure ◽  
Sine Wave ◽  
Delta Wings ◽  
Stability Derivatives ◽  
Mach Numbers ◽  
Leading Edges ◽  
The Stability ◽  
Pitch Damping ◽  
Flow Deflection

In this study, an attempt is made to evaluate the effect of first arched ends on the damping derived due to the pitch rate aimed at the variable sine wave bounty, flow deflection angle δ, pivot position, and the Mach numbers. Results show that with the escalation in the bounty of the complete sine wave (i.e., positive amplitude) there is an enlightened escalation in the pitch damping derivatives from h = 0, later in the downstream in the route of the sprawling verge it decreases till the location of the center of pressure and vice versa. At the location where the reasonable force acts, when we consider the stability derivatives in damping for the rate of pitch q, there is a rise in the numerical tenets of the spinoffs. This increase is non-linear in nature and not like for position near the leading edges. The level of the stifling derivatives owing to variations in Mach numbers, flow bend approach δ, and generosity of the sine wave remained in the same range.

The Estimation of the Non-Linear Lift of Delta Wings at Supersonic Speeds

1963 ◽  
Vol 67 (632) ◽  
pp. 476-480 ◽  
Author(s):  
L. C. Squire
Keyword(s):  
Mathematical Model ◽  
Linear Theory ◽  
Free Stream ◽  
Separated Flow ◽  
Leading Edge ◽  
Delta Wings ◽  
Non Linear ◽  
Leading Edges ◽  
The Mathematical Model ◽  
Slender Wing

Summary:Up to the present most of the methods used to calculate the flow over delta wings with leading edge separations have been based on slender wing theory. In this paper one of the simplest of these methods is carried over to linear theory and the overall lift calculated. In general the results are in agreement with experiment, in particular both show a fall in nonlinear lift as the leading edges of the wing approach the free stream Mach angles. The discrepancies which exist appear to arise mainly from the use of linear theory rather than from the mathematical model introduced to treat the separated flow.

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