The 1,158th lecture to be given before the Society, “Engines for Supersonic Air Liners” by Dr. R. R. Jamison, B.Sc., F.R.Ae.S., A.R.I.C. and Mr. R. J. Lane, Diploma of Graduate Studies (Birmingham), G.I.Mech.E., of Bristol Siddeley Engines Ltd., was given on 24th March 1960, at the Institution of Mechanical Engineers, 1 Birdcage Walk, London, S.W.I. The Chair was taken by Air Commodore F. R. Banks, C.B., O.B.E., C.G.I.A., F.R.Ae.S., Hon.F.I.A.S., M.I.Mech.E., M.Inst.Pet., Vice-President of the Society.

Introducing the lecturers, Air Commodore Banks said that after receiving his education at the South African College and the University of Cape Town, Dr. Jamison joined Rolls-Royce in 1937 and had remained with that Company until 1950, when he joined Bristol Aero-Engines Ltd.–now Bristol Siddeley Engines Ltd. He was Assistant Chief Engineer and Head of the Ram-jet Department and since 1950 had been working on ram-jet development. He and his team were regarded as the specialists in this country–and probably in Europe– on controllable ram-jets. Mr. Lane, joint author with Dr. Jamison of the lecture, had graduated from the University of Birmingham and had served his apprenticeship at the Royal Ordnance Factory before joining Bristols. He was now working on ram-jet dynamics and gas-dynamics of ram-jets with Bristol Siddeley Engines Ltd.

There is a scarcity of specific design data which can be presented to the aircraft designer to enable him to assess the most suitable structural aluminium alloy for a high speed civilian transport aircraft. The problem is essentially due to the relatively low range of elevated temperatures, in which he is interested, coupled with the very long life requirements for a commercial transport aircraft flying at speeds at which it is possible to consider the use of aluminium alloys.

Although the firm with which the author is associated has a vast experience in the development and knowledge of aluminium alloys for aero-engine and gas turbine purposes, it has never been required, in the past, to consider engine applications much below about 200°C, and the design data, which was determined over many years and provided as a service, satisfied the engine designers if the period of test was up to 1,000 hours. On the other hand, to the designer of aircraft for subsonic flight, kinetic heating is no problem at all, and he is quite satisfied with a knowledge of the room temperature properties of the various alloys.

As a native South Australian, I feel particularly honoured to have been asked by the Adelaide Branch of the Royal Aeronautical Society to deliver this second lecture in the Memorial Series commemorating the historic flight of the Smith Brothers from the United Kingdom to Australia. Just a few months ago—on 10th December, 1959—we celebrated the fortieth anniversary of the epic arrival of the Vickers Vimy at Darwin. One thing emerges clearly from our aviation record in the succeeding forty years, and it is simply that no single event has had such a profound effect on that record as the remarkable, trail-blazing flight of the Smith Brothers. If we came of age as a nation on the cold dawn beaches of Gallipoli on 25th April, 1915, then just as surely we won our wings as a nation on that hot summer afternoon of 10th December, 1919, when the Vickers Vimy touched down at Fanny Bay aerodrome, Darwin. We have, I think, continued to wear those wings with considerable distinction ever since.

Two interesting flow phenomena have been observed during the course of some transition measurements carried out on a swept-back wing with a curved tip. Firstly, the influence of leading-edge sweep angle on the type of instability responsible for transition has resulted in two distinct types of transition occurring simultaneously over different portions of the wing under certain critical conditions. Secondly, unlimited spanwise turbulent contamination of the flow was observed with an excrescence located close to the leading edge. The circumstances in which this occurred are believed to be somewhat exceptional, although much further work is desirable on this point.

Hilton has described a relatively inexpensive subsonic ram-jet installation which may be used as an aid to technical education. This type of equipment should serve to enable students to undertake performance studies of propulsion systems. To this end, this author would like to elaborate on one of the testing phases suggested by Hilton, that is, the tests on combustion systems with direct coupling to the air supply. It is the purpose of these remarks to present some previous observations on the combustion characteristics of a subsonic ram-jet which will serve as a useful demonstration as well as to provide areas of interest for academic investigations.