An Address by the President, Sir George Edwards, C.B.E., B.Sc, F.R.Ae.S., was given before a large and distinguished audience of members and their guests at Church House, Westminster, London, S.W.1, on 26th February 1958. Lord Hives, C.H., M.B.E., B.Sc, LL.D., Honorary Fellow, presided. At the end of the Address the second part of the Shell Petroleum Company’s film “High Speed Flight—Part II. Transonic” was shown for the first time.

Following the Presidential Address a Reception was held by the President and Lady Edwards at the offices of the Society, 4 Hamilton Place, W.1, which was attended by over 500 members and their guests.

The First Trenchard Memorial Lecture, “Lord Trenchard,” was given by Marshal of the Royal Air Force Sir Dermot Boyle, G.C.B., K.C.V.O., K.B.E., A.F.C., Chief of the Air Staff, at the R.A.F. Station, Halton, on 20th February 1958. This was the 30th main lecture of the Society to be given at a Branch and was held under the auspices of the Halton Branch. The large and distinguished audience included The Dowager Viscountess Trenchard and the present Lord and Lady Trenchard, Sir John Nott-Bower, Commissioner, Metropolitan Police, the Mayor of Aylesbury, a number of members of Council of the Society, the Commanders-in-Chief of Fighter Command, Technical Training Command, Maintenance Command and Home Command of the Royal Air Force, the A.O.C.s of No. 24 and No. 41 Group, the Commandants of Andover, Bracknell, Cranwell and Halton, and many other serving officers of the Royal Air Force.

The first Sir Henry Royce Memorial Lecture described the work of a brilliant engineer, who was directly responsible for the design of a long series of great engines. As a contrast, I have been asked to tell you about the work, not of an individual, but of a team. A team, moreover, that has had no responsibility for the final product, but whose task has been that of attempting to clear the ground and make the engine designers’ work less difficult.

The year 1957 has a certain significance in gas turbine history, in that it is the twentieth anniversary of several important early events. It was in March 1937 that the Engine Sub-Committee of the Aeronautical Research Committee discussed the internal combustion turbine and as a result recommended “that the Air Ministry should take up the question of the development of the internal combustion turbine as a matter of urgency and make all possible arrangements for its production at the earliest possible moment …”

Workers in the field of continuous combustion have long been aware of the importance of the part played by the aerodynamic factors in the satisfactory operation of combustion systems. Although only part of a complex process, the air flow in a combustion system can, to some extent, be studied as an isolated individual factor, without the complications of fuel injection and heat release. This may appear to involve a rather long step from reality, but observations of the basic “cold” flow conditions in such a system can provide a valuable basis for the prediction of the effects of variations in the equipment, particularly in systems conforming to a particular type.

Perforated Plates have been used at large angles of incidence to produce drag forces and evidence on their properties has been published by de Bray. Less appears to be known about the drag forces on such surfaces at zero incidence, although they are usually considered to be aerodynamically rough. This has been confirmed by Ambrose, who carried out pipe flow experiments using perforated liners which fitted tightly in the bore of a pipe. Perforated plates used in this way do not allow flow completely through them and give “pitted” surfaces. If a perforated plate is mounted so that it is possible for cross flows to occur between the main flows on both sides of the plate the drag forces on it may be affected, and in this case the perforations will be referred to as “holes.”

Coefficients for heat transfer from free rotating discs, at Reynolds numbers in excess of 4.8 x 105 have recently been obtained by Cobb and Saunders. These results are consistent with a limiting turbulent-flow heat transfer given by: —

Nu mean = 0.0172 Re0.80 . . (1)

The gustiness of the atmosphere is studied, among other reasons, because of its importance in producing loads on aeroplane structures much larger than the loads occurring in calm air.

Atmospheric turbulence is studied by observing the behaviour of aeroplanes passing through it, by observing the motion of balloons or other articles carried along by the wind itself, or by examining the fluctuations in velocity or direction occurring at a point fixed relative to the earth. The first of these methods is the most flexible and is the most convenient for aeronautical investigators.

This Note Gives a simple relationship between the zero-lift wave drag of the wing of a rectangular wing and body combination and the wave drag of the portion of the gross wing blanketed by the body, both evaluated as if isolated (i.e. ignoring the interference of other parts of the combination). The result is valid only when the tip Mach cones of the wing lie downstream of the blanketed wing. Detailed results are given for the case of wings with double-wedge section, the maximum thickness being at mid-chord.

Foster and Haynes recently suggested the possibility of measuring the rotary stability derivatives of an aeroplane by testing a suitably distorted model in a wind tunnel. This possibility has been examined for an isolated wing by the authors and has been found to be in error for the derivatives due to rolling and yawing.

In what follows it will be assumed that thin aerofoil theory and Prandtl’s lifting line theory may be applied.

I Should like to raise a point on the projected rear-engined jet air liners now under active consideration by several major British firms and of which “artists’ impressions” have recently been published, the latest being the V.C.10.

The rear-engine layout has so many advantages that its use seems entirely logical, but I am curious to know whether or not such a design has been investigated with a noseplane layout in preference to the conventional tailplane. I have been interested in this possible configuration for some years and put the idea forward in a short Branch lecture at Derby when it appeared that quite a few of those then present agreed in broad principle.