The design of a thrust chamber for a rocket propulsion system is a challenging task. The thrust chamber has to be designed for minimum structural weight with an adequate factor of safety. This calls for a thorough knowledge of various structural loads, both internal and external, and the behaviour of the structure in flight. This paper presents the design and structural analysis of a pressure vessel used as thrust chamber for a rocket propulsion unit. The effects of kinetic heating, thermal stress, spinning and various aerodynamic loads and their mutual interactions are accounted for in this analysis. Based on a detailed stress analysis of the components and a modal/structural dynamic analysis of the flight vehicle as a whole, in which the thrust chamber is the main load bearing member, the required mechanical properties of the thrust chamber are obtained.

Today we speak of the quality of life and the need to improve the quality of the environment. The removal of all kinds of pollution from our environment is a laudable aim and for some types of pollution positive action and an awareness of the problem can make improvements with a minimum of cost. However, in the case of most forms of pollution, and this includes noise, improvement in the quality of the environment can only proceed at a price. Thus there is considerable need for phased reductions in pollution and future planning with imposed realistic targets is paramount. In this region of social planning the problem of cost benefit analysis cannot always be applied and pressures are exerted to directing funds for economic gains and combating other pressures in national and international life in directions which lead away from pollution control. Nevertheless improvements to the environment dependent on the supply of finance can only be achieved, all other things being equal, when the economic state of a country is stable and attention of governments is directed with a willingness to achieve what at first sight is a downright impossibility.

It is my very great honour to be asked as an operator to cover the Bell 212s part in the story of IFR operation of medium helicopters.

None of us should forget that two great British companies have for years been blazing a trail in the IFR operation of two helicopters, the S-61 and the Wessex 60, and I can only assume that it was because Irish Helicopters was, I understand, the first operator to put the CAA approved Bell 212/IFR into operation that the privilege of giving this talk has come my way, and I speak humbly and mindful of the invaluable efforts of others before us.

In a recent paper, Gibbings has made an interesting comparison of the length of two-dimensional contractions based on three criteria, namely:

1. (1) the rapidity with which the boundary slope approaches its zero value;

2. (2) the rapidity with which the centre-line velocity approaches its asymptotic value; and

3. (3) the degree of uniformity of the velocity expressed as a percentage of its mean value.

The first meeting of the 1928-29 Session of the Royal Aeronautical Society was held in the rooms of the Royal Society of Arts, John Street, Adelphi, London, W.C.2, on Thursday, October 4th, 1928.

The President : Mr. North is one of the foremost designers in the country. Since early in 1911 he had devoted his activities exclusively to aeronautics and for many years had been responsible for the design of all aircraft produced by Boulton and Paul, of Norwich.

Mr. North had been very intimately connected with the design of the Government airship now in an advanced stage of construction at Cardington. His great experience of light steel structures had been utilised to the full in this connection.

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.

In the vibration of isotropic rectangular plates, the phenomenon of the simultaneous excitation of two separate modes having equal frequencies is well known. Wallerobserved complex nodal patterns on isotropic rectangular plates, and she stated that such combinations were possible because of the internal damping of the plates, which reduced the sharpness of resonance.

Warburton considered the existence of modes m/n±n/m for a clamped plate and showed that when a plate is square, for the mode 4/2 + 2/4, the nodal lines do not lie parallel to the edges of the plate. Furthermore, it was proved that for a square clamped plate, the modes m/n±n/m have discrete frequencies.

The first two US/UK co-operative satellites, Ariel 1 and Ariel 2, were put into orbit in April 1962 and March 1964, and both functioned most successfully. The lecture describes the NASA Pulsed Frequency Modulated telemetry system, including the methods used to store and transmit the data to ground stations, the digitising techniques used to prepare these data for entry into a computer and, finally, the organisation of the central data handling operations to the point where the partially or wholly reduced results were handed over to the various experimenters for analysis.

The aviation industry has not yet given much attention to the development of rotary winged machines as specialist agricultural tools which would help to make farming easier, more efficient and more productive. The emphasis is, and naturally has been, on the development of the immediately bigger markets for military aircraft. It is understandable, if unfortunate, that the farmer has to wait his turn well down in the queue of various armed forces specialists. He is waiting for aviation to turn the focus, some day, of its technical knowledge and research resources onto the way that the versatility, manoeuvrability and usefulness of the helicopter can be used to grow more food, timber, wool and other natural products.

I feel greatly honoured having been invited to deliver the Second Handley Page Memorial Lecture and, indeed, grateful for the opportunity to pay tribute to a great Englishman and aeronautical pioneer, who for 40 years was my personal friend and, for over 30, my Chief. As no other man, he has decisively influenced the course of my life.

In this paper some experimental results related to a calibration model (the Standard Dynamics Model, SDM) are presented.

The wind tunnel test activity is based on static force measurements and flow visualisations. The behaviour of the fuselage on its own is analysed and a correlation with some available prevision theories for the onset of asymmetries on ogival forebodies is proposed.

A complete set of static data for the SDM is introduced, evaluating the main aerodynamic interactions between the various elements of the configuration.

A series of flow visualisations was performed to verify with qualitative results the validity of the conclusions found from the analysis of the static coefficients.

The flow in a two-dimensional plane wall jet with different initial gaps between the nozzle exit and the leading edge of the wall was probed at various stations along the jet. The jet slot thickness and the velocity were kept constant. It was found that the region close to the leading edge of the wall behaved like a transforming region where the type of flow changed from a free jet to a wall jet. The length of this region, which depended directly on the gap size, was so short for small gaps that the gap effects were found to be negligible. In addition, it was found that the inner layer velocity distribution of a wall jet did not follow the classic one-seventh power law.

In a recent note in the Journal, Morley and Bryce discuss the problem of natural vibration with a damping force proportional to a power of the velocity. They address themselves particularly to the problem of interpreting experimental measurements, and mention an application of the study of an elasticity in metals. They were apparently unaware of previous analytic studies of this problem, and their analysis is somewhat inaccurate in indicating that the full-cycle logarithmic decrement rather than the half-cycle logarithmic decrement characterises the damping.

It is intended here to outline the previous analytic studies, to present the essential results, including those which can be directly employed in the interpretation of amplitude measurements, and to mention typical applications.