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Aarhus Kommunes Biblioteker (Teknisk Bibliotek), Ingerslevs Plads 7, Aarhus, Denmark. Representative: V. NEDERGAARD PEDERSEN (Librarian).

AERONAUTICS owes much to the selfless devotion and enthusiasm of its early pioneers. As was noted by the author in the Fourth Lanchester Memorial Lecture,1 Queen Mary College can claim to have the oldest established University Department of Aeronautical Engineering in the country due to the pioneer work of Dr A. P. Thurston, a graduate of the College, t It was in 1908 that he decided to establish an Aeronautical Laboratory there. He inspired the interest and support of like‐minded friends and Mr P. Y. Alexander, in particular, contributed a major part of the funds required to equip the laboratory. From Professor J. L. S. Hatton, the then Principal of the College, Dr Thurston received warm encouragement and the space for the venture, but College funds were then less than adequate for its longer established activities, and so the College could not afford to offer financial support to the new venture in its early days.

AN approximate solution of the boundary layer equations recently completed involved the assumption of a velocity profile through the boundary layerdepending on two parameters. As a result the problem was reduced to that of the construction and solution of two equations governing the variation of these parameters around the surface of the cylinder considered. Earlier solutions, such as Pohlhauscn's, have made use of a single parameter only and have employed Kármán's momentum integral for its determination, but the additional, parameter now introduced necessitates the use of a further equation. It is the purpose of the present note to discuss and illustrate the properties of the second condition that was selected.

WITH reference to the article on the “New Transformed Wing Sections,” by Piercy, Piper and Whitehead, (P) in the November, 1938, number of AIRCRAFT ENGINEERING, it is of interest to note a very simple approximate formula for the symmetrical type of section. This formula is:

THE greatly increased transition Reynolds numbers now attained in the boundary layers of cylinders having favourably shaped sections have renewed interest in the solution of the equations of steady flow in a thin boundary layer. It is familiar that the scries solutions of Blasius and Hiemenz, improved by Howarth (ref. 1), and of Falkner (ref. 2) become severely restricted in range when applied to cylinders having other than bluff sections. But it appears that a series solution of substantially greater range is possible, at least for symmetrical flow, provided that the nose of the section is rounded. This problem forms the subject of Section I of the present paper.

ANOTHER paper (Ref. 1) establishes a new approximate solution of the boundary layer equations devised to meet difficulties that are encountered in applying earlier solutions to laminar flow aerofoils and similarly thin cylinders. The advantage is in respect sometimes of accuracy, sometimes of applicability. The solution is a little unwieldy in its general form, however, and the present paper describes simplifications to facilitate rapid technical use. They are of two kinds, one being much more drastic than the other, and that first given, or both, may be used according to the nature of the problem and the accuracy required. Examples suggest that the resulting loss of accuracy and applicability will be small in most instances. This matter is described in Section I.

THE recently developed families of mathematical wing profiles have already been investigated theoretically in two papers. It is hoped, however, that these sections will not be confined to purely scientific work, but will find a place in design. A description in more practical terms is therefore of interest.

AIRCRAFT ENGINEERING was born in March 1929 of the belief that the emerging technology from which it took its title would become a fundamental element of engineering progress. The keystone of its policy was that it would attempt to meet the needs of engineers and students working in this field and that its contents should be ‘written by engineers — for engineers’. That this venture was fully justified has been amply vindicated by the achievements of the industry during the ensuing 41 years — as recorded in the first 500 issues of this Journal, the major milestone celebrated this month. This is a propitious occasion on which to review the record to date because, although aviation has always been about looking forward, history is instructive and it is the impressive performance of the aerospace industry to date that inspires and motivates confidence in its future.

A method is given for the design of a two‐dimensional wind tunnel contraction for incompressible inviscid flow. The contraction is considered to join parallel channels of different width and is of finite length. The contraction boundary consists of two curved portions fairing smoothly into the channel walls at the upstream and downstream ends and a straight portion in between joining the other ends of Ihc curved portions. The shape of the boundary is determined by specifying: (i) constant velocities along the curved portions and (ii) the angle of inclination of the straight portion to the tunnel axis. The solution to the problem is obtained by working in the hodograph plane. For this purpose the contraction is considered to be made up of two distinct parts, upstream and downstream, and the solution is worked out for each separately. Results are given in tabular form for differing values of the above parameters (i) and (ii). It is hoped that the results will be found useful in the design of most low‐speed tunnels and particularly those with large contraction ratios. The results given here have been used in the design of a smoke tunnel (contraction ratio 15 to 1), a model of which has been built and tested with satisfactory results.

THE purpose of this article is to present a mathematical treatment which has been found extremely useful in the design of spiral springs since it enables us to determine the physical dimensions of a spiral spring, and also its behaviour when subject to a straining action; i.e. the change of the radius of curvature at any point, change in the number of coils or in the spacing of coils. The following method concerns itself only with the spiral springs whose coils throughout the whole range of deflexion are free, i.e. do not touch one another, and also the springs which become completely solid at the maximum deflexion.