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The critical Mach number, lift-to-drag ratio and drag force play important role in the performance of the wings. This paper aims to investigate the effect of taper stacking, which has been used to generalize wing sweeping, on those parameters.

The results obtained are based on steady-state turbulent flowfields computations. The baseline wing is ONERA M6. Various wing planforms are generated by linearly or parabolically varying the spanwise stacking location. The critical Mach number is determined by changing the freestream Mach number for a fixed angle of attack. On the other hand, the analysis of the drag force is carried out by changing the angle of attack to keep the lift force constant.

By changing the stacking location, the critical Mach number and the corresponding lift-to-drag ratio have increased by around 7 and 3%, respectively. A reduction of 12.8% in total drag force has been observed in one of the analyzed cases. Moreover, there exist some cases in which the values of drag reduce significantly while the lift is the same.

The results of this new stacking approach have implied that the drag force can be decreased without decreasing the lift. This outcome is valuable for increasing the range and endurance of an aircraft.

This work generalizes wing sweeping by modifying the taper stacking along the span. In literature, wing sweep is enhanced using segmented stacking of taper distribution. The present study is further enhancing this concept by introducing continuous stacking (infinite number of stacking segments) for the first time.

AT the present time turbojet aircraft types which are capable of level flight Mach numbers well into the supersonic range are appearing in increasing numbers. Yet, while this represents in a sense a new phase in the evolution of piloted aircraft, from the point of view of the propulsion engineer it is rather the end of an era, in that hitherto the turbojet engines employed have been essentially subsonic engines suitably strengthened. Henceforth we may expect to see the use of engines specifically designed for the appropriate range of Mach number, and it is the purpose of this article to review some of the implications of this change of outlook in so far as they affect the prediction of engine performance.

As part of the R.A.E.‘s critical study of the aero‐isoclinic principle of wing design, a detailed examination was made of high‐speed aeroelastic effects on manoeuvre point, with special reference to the effect of rearward movement of local aerodynamic centres at super‐critical Mach numbers. From the results of calculations, using the method of R.A.E. Report No. Aero. 2320, it is concluded that as regards possible shifts of manoeuvre point, the aero‐isoclinic wing is generally superior to the conventional wing. For tailless aircraft, application of the aero‐isoclinic principle makes it possible to employ wings of an aspect ratio much larger than is considered practicable with conventional design. Structural design of a flutter‐free aero‐isoclinic wing entails radical departures from orthodox procedure, and with tailed aircraft it is therefore probably preferable to adapt the design of the tail plane and its attachment, to cope with the destabilizing deformability effects of a conventional wing, than to eradicate such effects at the source by aero‐isoclinic design of the wing.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued

A Summary by Dr. Alexander Klemin of the Papers Presented Before the Fourteenth Meeting of the Institute held at Columbia University, New York, on January 29–31, 1946. AERODYNAMICS IN spite of increased wing loadings, the use of full span wing flaps has been delayed, because of inability to find a suitable aileron. The Development of a Lateral‐Control System for use with Large‐Span Flaps by I. L. Ashkenas (Northrop Aircraft), outlines the various steps in the aerodynamic development of a retractable aileron system well adapted to the full span flap and successfully employed on the Northrop P‐61. Included is a discussion of the basic data used, the design calculations made, and the effect of structural and mechanical considerations. Changes made as a result of preliminary flight tests are discussed and the final flight‐test results are presented. It is concluded that the use of this retractable aileron system has, in addition to the basic advantage of increased flap span, the following desirable control characteristics: (a) favourable yawing moments, (b) low wing‐torsional loads, (c) small pilot forces, even at high speed.

IN the first of these articles it was pointed out that normal supersonic flow can be described theoretically, to a first approximation, by the linearized equation of motion. This has the form of the wave equation and governs first order disturbances to fields of uniform flow; for example, flow past thin wings or slender bodies at small angles of incidence, and flow through ducts of varying cross‐section. In the same way small disturbances in a purely subsonic stream can be described by a linearized equation of motion, which can be reduced to Laplace's equation by contracting the co‐ordinate normal to the direction of flow. Transonic flow, in which regions of both supersonic and subsonic flow occur, is not so easily represented.

A Paper, describing the Research work and flight testing that went into the first American jet‐propelled fighter aeroplane, prepared by Mr Clarence L. Johnson, Chief Research Engineer, the Lockheed Aircraft Corporation, and presented before the Fifteenth Annual Meeting of the Institute of Aeronautical Sciences, New York, January 1947.

RECENT developments in the design of supersonic aeroplanes and particularly the ducting problems connected with the installation of turbo‐jet and rocket engines have brought about a considerable increase in the complexity of calculations required for prediction of performance. This is especially true when several alternative solutions are considered and the final choice depends on the relative performance. Any graphical methods which can reduce this calculations work are therefore of considerable practical value.

IS there anything magic about the shape of a wing section? Asked to sketch the profile of a wing on the back of an envelope, one would have no difficulty in representing a shape which would probably, for most purposes, be adequate. Assuming this generalization to be true—perhaps it is a rather rash one—one might equally well question the need for an article on aerofoil design, or indeed the need for the long and painstaking research which, over the years, has been conducted on this particular subject. But it is this same research which, in the long run, has resulted in the recognition of certain general rules relating to aerofoil geometry, which are now taken so much for granted that they would probably be embodied in one's preconceived notion of what a wing section should look like. Recently, also, rather complicated theoretical techniques have made possible the design of profiles which, if manufactured faithfully and carefully in each detail, can provide a performance which is considerably better than any more arbitrary shaping to general rules would produce. Finally, of course, one must recognize that there are exceptional conditions where the application of conventional ideas is inadvisable, and where theoretical and experimental research is needed to suggest what is more appropriate. This article will be concerned for the most part with amplifying these remarks; but, by and large, it must be admitted at the outset that we cannot point to any revolutionary discontinuities in the progress of aerofoil design such as have characterized advances in the means of aircraft propulsion, or structural design.