A Note on the Evaluation of the Supersonic Downwash Integral

1954 ◽  
Vol 5 (2) ◽  
pp. 111-118
Author(s):  
B. A. Hunn

SummaryTo calculate tail loads in flight it is necessary to know the angle of downwash at all points of the tailplane for any given value of wing incidence. Current trends in aircraft design place the tailplane off the plane of the wing. There exist solutions for the downwash in the z=0 plane for a delta wing with subsonic leading edges. This note gives a form of integral suitable for numerical evaluation which determines the downwash in the plane of symmetry (y=0) of a delta wing with subsonic leading edges. This note also points out an apparent error in Ref. 4 by G. N. Ward and gives a closed form for the downwash at a point whose forward Mach cone totally includes an arrowhead wing with supersonic trailing edges and whose centre line coincides with the axis of the cone.

2014 ◽  
Vol 9 (1) ◽  
pp. 29-38
Author(s):  
Aleksandr Vaganov ◽  
Yuri Yermolaev ◽  
Gleb Kolosov ◽  
Aleksandr Kosinov ◽  
Aleksandra Panina ◽  
...  

The experimental results of high level fluctuation excitation by external Mach’s wave in the boundary layer of delta wing model with blunt leading edges at Mach numbers M = 2, 2.5, 4 are presented. The exitation areas and mass flow pulsation levels in the conditions of subsonic, sonic and supersonic leading edges have been defined. It was found that the maximum value of the pulsations is 12–15 % and varies only slightly from the flow conditions around of the delta wing


1971 ◽  
Vol 24 (3) ◽  
pp. 355-370
Author(s):  
P. G. Reich

The main concern of this paper is with the limitations of techniques already commonly applied, and in the more promising points of application for new technology in navigation, surveillance and traffic control. In seeking the latter, some of the current trends in other fields, particularly aircraft design, are taken into account. Considerable emphasis is placed on the efficient use of land at airports, in view of the strength of feelings aroused in ‘the community’ by the questions of apportionment and exploitation of land resources.


1955 ◽  
Vol 6 (2) ◽  
pp. 149-163 ◽  
Author(s):  
G. N. Lance

SummaryA generalised conical flow theory is used to deduce an integral equation relating the velocity potential on a delta wing (with subsonic leading edges) to the given downwash distribution over the wing. The complete solution of this integral equation is derived. This complete solution is composed of two parts, one being symmetric and the other anti-symmetric with respect to the span wise co-ordinate; each part represents a velocity potential. For example, if y is the spanwise co-ordinate and x is measured in the free stream direction, then a downwash of the form w= - α11 Ux|y| is symmetric and will give rise to a symmetric potential, whereas w= - α11 Ux|y| sgn y is anti-symmetric and gives rise to an anti-symmetric potential. The velocity potentials of such flows are given in the form of Tables for all downwashes up to and including homogenous cubics in the spanwise and streamwise co-ordinates. Table III gives similar formulae in the limiting case when the leading edges become transonic; these are compared with results given elsewhere and serve as a check on the results of Tables I and II.


1962 ◽  
Vol 66 (615) ◽  
pp. 163-176
Author(s):  
Robert G. Legendre

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.


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