The association of a gas turbine with a piston engine is by no means a recent conception. As early as 1924 a Napier Lion Series V engine was equipped with a turbine in the manner shown in Fig. 1, the exhaust gases being fed into the turbine to provide all the power to drive the engine supercharger.

At a later date during the 1939-1945 War, many engines were installed in operational aircraft fitted with “turbo-chargers” of the type shown in Fig. 2, in which an exhaust activated turbine drives a subsidiary blower boosting the air intake of the normal engine supercharger.

The paper discusses the application of wind tunnels to aircraft design and consideration is given to the potentialities and limitations of types designed specifically for industrial use. Arguments affecting the choice of type, size and speed are stated and a detailed description is given of a particular tunnel which has very steady and even flow with a reasonable turbulence level. This description covers the aerodynamic and engineering design, the electrical driving arrangements and the six-component automatic balance.

A description is also given of a new type of high speed tunnel which has recently been put into operation. This is of the simple straight-through type and is driven by a jet engine acting as an ejector pump; the exhaust heat is used to control humidity and prevent condensation in the working section. This tunnel reaches a Mach No. of 0.9 when empty, and over 0.85 with a model in place. The Reynolds No. is 1.6 x 106 for a three-dimensional half model and 5 x 106 for two-dimensional wings.

Two design conditions for an axial flow compressor stage are proposed and examined. These are, the constant reaction condition (incorporating I “ radial equilibrium ”), and the condition that the Mach number at inlet to the rotor shall be invariant with radius. In addition, the combination of these two properties in one stage is considered. It is found, with further assumptions regarding the nature of the flow, that a forced vortex type of flow will satisfy both design specifications. The forced vortex solutions for the various cases are presented, and for constant Mach number at inlet to the rotor, more general solutions are given.

Multitudes of young- men are starting to study navigation. As a rule it is only after many months of painful work that they come to see what it is all about –many of them never get to that point at all.

In none of the books on navigation have I been able to find a simple picture, defining each step in the reasoning that enables us to navigate by the stars. Hence this effort. As set out here the principles can be grasped by anyone.

A meeting of the Royal Aeronautical Society was held in the Lecture Hall of the Institution of Mechanical Engineers, Storey's Gate, St. James Park, Westminster, London, S.W.I, on Thursday, February 15th, 1945, at which a paper entitled “Aeroplane Wheels and Brakes” was presented by Mr.J.Wright, A.F.R.Ae.S. In the Chair, the President, Sir A.H.Roy Fedden.

In aeronautical engineering the strength-weight ratio is so important, apart from the fact that the consequences of structural failure are generally more disastrous, that it becomes essential to investigate the loads and stresses in the various parts of the structures far more accurately and in much greater detail in order that smaller factors of safety may be used.

It is often possible, in the case of structures of a low order of redundancy which have to be designed to meet several different systems of loading, to select by inspection those members which may be considered to be the redundant ones, the elimination of which would result in an increase of the design loads in most of the remaining members. If the members are designed to such increased loads many members of the structure will be overstrong and unnecessarily heavy. The excess of strength of the various members of the complete redundant structure will almost certainly differ, so that the weight of the whole will be increased above the essential in a greater proportion than the strength.

In Rocketry, the definition of Specific Impulse is given variously as Thrust per unit mass of propellants consumed per second and Thrust per unit weight of propellants consumed per second. The second definition is convenient in giving units in seconds, but is unsatisfactory in that the weight of a given mass of propellants depends upon gravitational attraction, and decreases with altitude.

This investigation is concerned with the stresses in a hollow circular cylinder of constant wall thickness, and closed by flexible plates, also of constant thickness. The cylinder is subjected to the combined action of an internal pressure and an axial force, both of which are statically applied. Although the particular case envisaged is that of a shock absorber, there are other engineering elements to which the analysis is applicable. Any closed circular cylinder of constant wall thickness subjected to an internal pressure is within the category. In a paper, Dr. D. M. A. Leggett investigated the case of an oleopneumatic shock absorber with rigid end plates, and what follows is an extension of his paper. As would be expected, the flexibility of the end plates causes a reduction in the flexural stress.