After a brief review of the classification of the couplings from the kinematic and mechanical points of view, the problem of aircraft engine Interconnection is introduced, together with some solutions which have made it possible to overcome the difficulty presented by the joint, at the expense, however, of some other mechanical requirements. The troubles experienced with couplings are to be blamed on the following three aspects of the conventional coupling designs: the use of gear-tooth couplings, sliding splined shaft arrangements, and the use of couplings of excessive weight. Possible improvements in the conventional designs using splined shafts are described, also the correct means of ensuring lubrication and the possibility of avoiding the need of lubrication by use of elastic distortion. Some Information is given about the effect of materials to be used for joint faces. The author then deals with coupling systems which are essentially based on the elastic property of materials. Three systems are investigated: flexible shafts, diaphragms and flexible couplings. Although flexible shafts are excellent for small misalignments, they do not permit axial movements of which diaphragms and flexible couplings are capable. The author then deals with sliding motions by recirculation of rollers which considerably extend the possibilities of axial movement. While couplings are devices normally intended to (ink up adjacent units, they become transmissions when units are some distance apart, and the typical feature of transmissions is that they require to be supported on one or more bearings. Straight and curved transmissions are presented, together with a brief survey of the following problems:

Typical test results are given, including those for the Breguet 941 curved transmission which has been run for 17 000 hours, that is 3.6 X 1010 revolutions, with only one relubrication at 10 000 hours. A short length instructional film showed the operation of a flexible bearing under critical speed conditions (this bearing is a part of the Breguet 941 curved transmission), and also demonstrated the endurance of the joints using sliding-type flexible couplings.

Although the science of Hovercraft is still in its infancy, sufficient promise is already being shown to indicate a commercial and military future as alternative means of transportation. Since transportation involves power, and power involves noise, it is imperative that even at this early stage, development does not proceed in a direction which involves excessive noise and in so doing builds up the embarrassing situation for itself of the kind now occurring with aircraft at London Airport.

To give an example, one of the major problems in establishing a third airport for London is obtaining a quick method of communication between such an airport and the centre of the city. Unless this can be achieved, the advantages of supersonic travel will be nullified. The roadways and railroads are already full and alternative forms of travel must be found.

Air Transport Auxiliary (ATA) came into existence soon after the outbreak of war in September 1939. Its flag was finally hauled down on 30th November 1945. In these six years it grew from an idea in the mind of Gerard d'Erlanger to an organisation employing at its peak in 1944, 550 male pilots, 108 women pilots, 109 flight engineers and a ground staff of about 2800, a total of around 3500 people.

Experience leads me to the conclusion that the coefficient of relative man-power (and hence economic) efficiency of a specialised civilian as opposed to a necessarily unspecialised Service organisation is between 3 and 5, hence that ATA released for more direct operational war services between 9000 and 15000 men and women.

Rotating-Drum (or mirror) cameras have often been used in conjunction with schlieren apparatus to investigate the performance of shock tubes. In the conventional arrangement the working section is viewed through a slit parallel to the axis of the tube, which is also parallel to the drum axis. The photographic record obtained on a film attached to the drum represents the distance-time (x, t) diagram of the propagation of (density) disturbances in the working section. The quantitative information obtainable from such records is usually limited to the speed of propagation of such disturbances.

When stagnation heat transfer rates are expressed in terms of free stream flow properties, the following combination of terms is found to occur: —

where ps pressure at the stagnation point

p∞free stream pressure

U∞free stream velocity

Dnose diameter

ßstagnation point velocity gradient.

Since it is too complicated to obtain analytically the stress distribution in a plate containing two reinforced circular holes under uniaxial tension, the stress distribution along the inner edge of a reinforcing ring will be determined experimentally in this report.

The relationship between σθ/p at the inner edge of a ring, the dimensions of a ring and the distance between the centres of two holes will be investigated. Experiments are done in the cases when the uniform load is applied in the perpendicular or parallel direction to the centre line (see Figs. 1 and 2).

An established method is used to find the stresses in a square plate pierced by a central circular hole. Although the method is not new, the problem is a practical one which has attracted some interest and for which some excellent experimental results are available.

The general problem of a finite plate containing a circular hole was examined by Sekiya who selected various combinations of the general solutions of the biharmonic equation in polar co-ordinates such that the boundary conditions on the hole were satisfied exactly. The boundary conditions on the sides of the plate were satisfied approximately by collocation. The same approach has recently been suggested by Waters for the particular case of a stress-free hole.

The dynamic analysis of heated structures is of considerable importance. Significant heating of a flight vehicle may take place at high speed causing reduction in its structural stiffness and vibration frequencies. Such changes in frequencies and mode shapes can substantially affect various static and dynamic aeroelastic instabilities.

In general, availability of a similarity law simplifies the solution of a problem. The following presentation studies similarity relations existing between an unheated vibrating cylinder and one with temperature gradient across its thickness.

The use of multilobed pressure vessels is not new. Such structures have been used in civil engineering applications for many years. It has been recognised that substantial weight savings are possible by reducing the radius of curvature by lobing. Usually the resulting discontinuity stresses at the junctions of the lobes have been balanced by attaching flat plates.