bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Development of Small Aircraft Gas Turbines in France
Authors: Szydlowski Joseph 
Published: July 2016

To Describe the development in France of small gas turbines of necessity confines one to the products of the Turbomeca Company. It is therefore not through lack of modesty that I speak of those engines which have been designed and built under my direction.After the Second World War our aims were quite ambitious. We envisaged the creation of jet engines up to 6000 kg (13200 lb) thrust, as well as the aircraft to suit. We soon realised that such ideas were far beyond the industrial and financial possibilities of the time.
Stresses in a Square Plate Having a Central Circular Hole
Authors: Davies C. A. O. 
Published: July 2016

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.
Similarity Relations for Vibrating Cylinder with Temperature Gradient across the Thickness
Authors: Modi V. J. 
Published: July 2016

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.
Drainage Criteria for Runway Surface Roughness
Authors: Moore Desmond F. 
Published: July 2016

SummaryThe main factor contributing to hydroplaning on slick runways is the existence of a squeeze film in the contact area between tyre and surface. The situation may be improved by optimising surface texture so that the asperities break through the water film in a minimum time. Two techniques are described for characterising surface texture: a superposition solution based on viscous channel flow and a dimensionless number approach involving size, spacing and shape factors. The “feel” of a surface is quantitatively obtained, and an outflow meter is described which, by directly measuring the mean hydraulic radius of runways, provides a comparison of their drainage abilities.
Aircraft Design Possibilities
Authors: Whitby R. H. 
Published: July 2016

I hope that I shall be forgiven if I deal only in part with this subject, and also if I approach it from the airline engineer's point of view, although what I have to say is a personal expression of opinion.Airlines are commercial undertakings and do not welcome change for change's sake. To improve service competitively from the point of view of time, regularity and safety and to encourage the continued growth of traffic through reductions in fares is the broad aim; it is against this background that, for example, the supersonic transport is being considered by the airlines. As you may have gathered, there is no marked enthusiasm. In due course, come it will, and traffic management plans must bear it in mind in considering future developments in Air Traffic Management. I am going to adopt the rather conservative attitude that most air traffic over the next two decades will be in aircraft much as we know them at present, and that if the growth in traffic leads to difficulties in Air Traffic Management then the main source of improvement must be sought in the system of management.
Balance of Helm and Static Directional Stability of Yachts Sailing Close-Hauled
Authors: Letcher John S. 
Published: July 2016

SummaryAn analysis is presented for equilibrium of yawing moments for a yacht sailing in the displacement mode in smooth water. The geometry of hull form and sail plan are quite unrestricted, although special attention is given throughout to currently popular types.The free-surface flow is simplified by a reflection technique. In cases where the hull form is appropriate, the hull hydrodynamics are treated by lifting-line theory: in other cases slender-body theory is applied. The sail aerodynamics are treated by methods taken from aerofoil theory. Some design charts are given and computation methods are suggested for practical design calculations.Static directional stability is treated theoretically and some general conclusions drawn regarding the influence of various characteristics on stability.Where the theory has been applied, results have agreed with the available experimental data within the limits normally provided for adjusting balance of helm. Changes of balance with angle of heel and static stability have been given by the theory at least qualitatively correctly; experimental results are, however, not available for comparison.
Dissertation on “The Rank Technique” and its Application
Authors: Robinson John 
Published: July 2016

Summary“The Rank Technique” is a method for automatic selection of redundancies in the Matrix Force Method. The method was developed for the complete linear analysis of general plane frames, but is equally applicable to other forms of two- and three-dimensional configurations whose state can be expressed as a system of linear equations. An attractive feature of the method is that the structure is systematically and automatically investigated to determine its basic characteristics. The first point considered is whether the structure is stable or unstable for the prescribed load conditions; if stable, whether determinate or redundant and if redundant, the degree of redundancy. A consistent set of redundants is automatically isolated. For general structures the technique automatically generates the basic and redundant load systems in an indirect manner which can be made readily available, if required. The initial development of “The Rank Technique” was carried out in collaboration with Robert R. Regl and is given in reference 1.
A Note on the Supersonic Panel Flutter of Oblique Clamped Plates
Authors: Kornecki A. 
Published: July 2016

Summary and IntroductionRecently, the effect of sweepback on the boundaries of supersonic panel flutter was studied in Ref. (1), (2) and (3), all of them dealing with rectangular plates.The present note considers the problem of panel flutter boundary of plates in the shape of a parallelogram with all edges clamped.It is assumed that Ackeret's theory of linearised two-dimensional supersonic aerodynamic loading gives an adequate approximation to the air forces for high Mach numbers.The criterion of instability is the coalescence of frequencies.A four-mode solution was obtained by means of Galerkin's method using first two streamwise and spanwise deflection modes. The results are represented in the form of diagrams for different aspect ratios(a/b)and sweep angles(ϕ).
Transonic Similarity Correlation of the Terminal Shock Jump on Aerofoils
Authors: Mabey D. G. 
Published: July 2016

This note illustrates the correlation of the pressure distributions measured on three NACA 16-series aerofoils at subsonic and transonic speeds. The transonic similarity parameters proposed by Spreiter are used for the subsonic, transonic and supersonic types of flow illustrated in Fig. 1.
The Hovertruck — 1
Authors: Bingham A. E. 
Published: July 2016

The phrase “Air-Cushioned Vehicle” describes the complete range of vehicles which obtain some or all of their support from a free pressurised cushion of air contained between the vehicle and the ground.Vickers’ interest in air cushion vehicles stems directly from the basic work carried out on the Hovercraft—one type of air cushion vehicle—by Mr. C. S. Cockerell and the initiative and encouragement displayed by the N.R.D.C. through its subsidiary Hovercraft Development Ltd.
The Hovertruck — 2
Authors: Evans E. W. B. 
Published: July 2016

A Great deal of information is available today which cannot over-emphasise what is at the moment, the serious plight of millions of people in the world and which will become more serious unless agriculture and science can continually develop new techniques to increase production.There is more than enough land in the world if only it can be developed and farmed. What is needed is capital, work and new ideas for its means, so that, if all are to be fed enough food, the grain production of the world must be doubled and the animal production tripled.
The Pilot's Viewpoint —2
Authors: Woolley D. H. 
Published: July 2016

The Agricultural pilot looks for the following qualities in his aircraft, and I suggest that he looks for them in this order of importance:Lively performanceDocile handlingPersonal protection in an accidentReliability of both aircraft and agricultural gear.I said that performance should be lively. Perhaps it should be not far short of exhilarating. Certainly in many cases in current operations it can barely be described as adequate. Of course, some conditions of work call for a higher performance than others, and it is not possible to talk about ideal figures without relating them to a specific operation. Compromise is inevitable, but the most exacting types of work must be kept always in mind. Admittedly, most suggestions for performance minima made by a pilot may call for engines and power loadings which will seem quite uneconomical to the operator, particularly as engine overhaul costs often appear to increase as the square of the engine power.
Design for Runway Conditions
Authors: Thomas J. W. H. 
Published: July 2016

The designer's task is always to choose the best compromise to meet the various conflicting requirements put upon him. This task is eased when these requirements and ways of meeting them are expressed precisely in numbers, which is so in most performance work, but rarely true of safety or reliability.In these latter areas the feedback of operational information shows when a problem exists and how important it is. For existing aircraft a solution must often be sought by ad hoc tests before the results of fundamental research are available.
Development of Guided, Tactical Missiles in France
Authors: Stauff Emile 
Published: July 2016

Before I attempt to describe the various missiles which we have developed, I feel it useful to give a brief review of the evolution with time of our technical group, of the position of this group in France and finally of the criteria which guided its choice of a working programme.Our technical team was formed in 1946 at the Arsenal de 1'Aéronautique, a government establishment. Its staff, at that time, comprised some ten engineers and specialists. In 1953, the Arsenal de 1'Aéronautique was turned into a company, the SFECMAS, which eventually merged with Nord-Aviation in 1955. The growth in manpower and facilities of the Nord missile group went on steadily during that entire period. The present staff amounts to some 900 engineers and specialists, who are employed only in laboratories, design, research and test facilities. This does not include the production side, which is dispersed among four plants outside the Paris Area.
Natural Vibration with Damping Force Proportional to a Power of the Velocity
Authors: Morley A. W. , Bryce W. D. 
Published: July 2016

SummaryThe friction force in many physical systems has been found to depend on a power of the velocity, the magnitude of which varies according to the damping mechanism. This note employs an approximate theory applicable to small damping to examine the free vibration of a single degree of freedom system in which the damping force is proportional to an unspecified power of the velocity.Correlation with experimental data on the internal damping of solid materials shows that this phenomenon also tends to obey a power law although discrepancies exist between the expected and observed behaviours. These arise from the interpretation of the damping coefficient and from the frequency dependence of the dissipated energy.
Packaged Liquid Rocket Motors
Authors: Neat W. N. , Page K. G. 
Published: July 2016

The relative merits and possible applications of liquid and solid propellant rocket motors have long been topics for discussion and controversy. The arguments for and against have been sharpened by the fact that the development of the two types of motor are usually vested in quite different teams of people. At the same time, a fair comparison has often been confused because the ultimate choice has been made for reasons which are really not technical at all, but instead depend on availability and the utilisation of already deployed capital resources.
Nevertheless, the merits and de-merits of the “conventional” (as opposed to the packaged) liquid motor and the solid motor can be simply defined with reasonable accuracy. The liquid motor is complicated, demanding at least some, and often a great deal, of attention before use. At the same time, it has a much greater performance potential, can be used repeatedly and can be designed to give variable thrust. The solid motor is simpler (although is getting less so), is cheaper (although this is getting less true) and demands less preparation. However, it has definite performance limitations, is inflexible in its output, and is often quite sensitive to its environment, whether during storage, carriage, or operation.
The Initiation of Projects
Authors: Blackwell B. D. 
Published: July 2016

In providing the introductory speech to the section of this Symposium which deals with The Initiation of Projects, I have both the advantages and disadvantages of the opening batsman. My advantage is that I can set the scene in the manner which suits my purpose and this, I propose, quite unashamedly to do and beg the Chairman’s forgiveness if I overlap too much.First I want to give you two quotations from recent presidential addresses to this Society and to the Institution of Mechanical Engineers. I found them both peculiarly relevant to the issues we are met to discuss.First, the Duke of Edinburgh in his recent Centenary Address to the Royal Aeronautical Society said, “Yet we all believe that it is ridiculous for a country which is supposed to be well advanced in engineering technology, to admit it cannot cope with aeronautics—the most advanced technology of them all.“
Reinforced Plastics for Jet Lift Engines
Authors: Gresham H. E. , Hannah C. G. 
Published: July 2016

Summary:—Extensive use of reinforced plastics has contributed significantly to the success of small VTOL engines, notably the Rolls-Royce RB 162 series in whose compressors it has been possible to demonstrate their versatility and ruggedness. The choice of reinforced plastics for such obvious reasons as lightness, specific strength and corrosion resistance has been fully justified, while apparent deficiencies in stiffness and rain erosion resistance have not proved embarrassing.Considerable use has been made of epoxy resin pre-impregnated sheet incorporating non-woven parallel aligned glass fibre, in particular the “Scotchply” series of “pre-pregs”. Exceptionally high fibre contents have been achieved, resulting in higher strengths and moduli than are usual with glass-reinforced plastics and furthermore, since Scotchply has proved so uniform in composition and ply thickness it has been possible to precision-mould most components with such accuracy that machining is eliminated—a major economic factor. Further economies have been achieved by minimising press curing times by the use of latent catalytic type hardeners for the resin systems which, in addition, confer long storage life and good heat resistance. The use of very thin sheet material has allowed much ply orientation within laminates, resulting in substantial and controllable variations in anisotropy, allowing properties to be tailored more nearly to meet the conditions imposed.
New Notation for Aircraft Dynamics
Authors: Melling R. 
Published: July 2016

Notations and nomenclature for aircraft dynamics and associated aerodynamic data have evolved over many years. Common usage broadly followed the ideas laid down by Bryan, Glauert, Bryant and Gates, and extensions eventually resulted in a conglomeration of symbols which generally impeded the efforts of students, teachers, and other workers and there was little scope for making further additions in a sensible way.Much work has been done at the Royal Aircraft Establishment to rationalise the position, and the resulting scheme is presented in RAE Technical Report TR 66200. In this scheme changes are kept to the minimum possible, existing concepts are retained, and considerable care is taken to provide a flexible system which allows an author a great deal of freedom as regards simplifying the notation in particular investigations—by omitting suffixes, for example. The RAE is confident that the new notation and nomenclature will overcome the inadequacies of existing systems.
The Derivation of a Formula for Thrust from Thermodynamic Energy Equations
Authors: Buchan A. L. 
Published: July 2016

It is usual to consider equilibrium between the forces and accelerations associated with individual fluid elements when deriving thrust formulae containing momentum terms. Thermodynamic energy equations for open systems, however, only rely on the premise that, as far as energy is concerned, what goes into a system must either come out or else build up inside.In thermodynamic textbooks a distinction is usually drawn between steady flow, involving no change of energy with time inside a system, and non-steady flow, which implies a rate of change of energy within the thermodynamic system under consideration.It is interesting to find that the thrust formula for a simple system, as shown in Fig. 1, may be derived directly from these thermodynamic energy equations by two alternative methods.
The Royal Aeronautical Society The First Fifty Years—1866 and All That
Authors: Laurence Pritchard J. 
Published: July 2016

“ God bless the Duke of Argyll!”In the Lecture Hall at Hamilton Place, London, of the oldest aeronautical society in the world, that Duke of Argyll, who became its first President in 1866, looks silently down upon those members who, less than a century later, succeeded so noisily to fly faster than the sounds of their own triumphant cries of success.
The Antiquity of the Royal Aircraft Establishment
Authors: Walker P. B. 
Published: July 2016

Apart from Royal patronage and the manifest concern with aviation, it must seem to many people that there is little in common between the Royal Aeronautical Society and the Royal Aircraft Establishment. Yet research into the lesser known activities of the early RAE has revealed not only a comparable antiquity but also a remarkable similarity in the early history of the two bodies. Both had to fight hard to stay alive, and often continuing existence depended upon a tenuous thread liable to snap at any moment.In its early years the Society was essentially a group of dilettante with all the advantages as well as the disadvantages that this entails.
Aircraft Structures
Authors: Howard H. B. , Chitty L. , Watts H. C. 
Published: July 2016

It was with some trepidation that I accepted the Society's invitation to contribute a Chapter to this Centenary issue. As the Lord Chancellor in Iolanthe has it,“But though the compliment impliedInflates me with legitimate pride,It nevertheless can't be deniedThat it has its inconvenient side.“Nearly all those mentioned in the following chronicle of British achievements have known me personally; many have been my colleagues. It would be unfortunate if what I have said, or have failed to say, about their work were to disturb hitherto harmonious relations.
With Frewen Jenkin at the Ministry
Authors: Aitchison Leslie 
Published: July 2016

It was wise of Duff Cooper to remind us that “old men forget”, and I fully agree with him. But, like so many others, I find myself remembering more about the events of fifty years ago than I do about those of yesterday.My entry into the world of aeronautics was brought about by R. V. Southwell (now Sir Richard), who asked if I would take a metallurgical post in the RNVR at Kingsnorth. I was, however, placed in the Materials Section of the Technical Department of the RNAS.The head of the Materials Section was Commander Charles Frewen Jenkin.
British Aircraft Design
Authors: Macmillan Norman 
Published: July 2016

Between 1910 and 1966 British aircraft design fell into certain distinct periods, each of which, more or less irrespective of the number and arrangement of the power units, may be recognised by its common structural pattern. In each period, as might be expected, there were exceptions to the contemporary common pattern, often only experimental, or built in srrall numbers.In the first period, which lasted until about 1924, wirebraced wood airframe structures were the common pattern.
Early Days
Authors: Bulman Major G. P. 
Published: July 2016

When one is young a century seems almost an aeon, mythical in its earlier days, peopled with men whose names are forgotten, or remembered only as seen on mouldering tomb stones in village churchyards. But to me, although only in the earlier seventies, the hundred years spanned by the Aeronautical Society of Great Britain (as it was originally called) is little more than “an evening gone”.P. Y. Alexander, an engine enthusiast, was one of its early members, and a close friend of an uncle of mine, and I met him in his later years.
IT'S NOT JUST THE TECHNOLOGY, IT'S THE SURROUNDING SYSTEM: HOW RESEARCHERS IN ECUADOR FOUND WAYS TO MAKE THEMSELVES USEFUL TO FARMERS THROUGH QUINOA AND LUPIN SEED SYSTEMS
Authors: MAZÓN NELSON , PERALTA EDUARDO , MURILLO ÁNGEL , RIVERA MARCO , GUZMÁN ALFONSO , PICHAZACA NICOLÁS , NICKLIN CLAIRE 
Published: July 2016

SUMMARYAgriculture research often focuses on a technical problem. However, the most effective researchers usually intuit that this entry point is not sufficient to make themselves useful to farmers and nudge systems. Yet non-technical work frequently goes undocumented leaving many of the drivers of success unstudied. This paper attempts to understand the factors that contributed to the wide utilization of native crop varieties and species that were being promoted by the Ecuadorian National Agriculture Research Institution. The results show that what really made a difference in farmers' lives and the overall food system was increasing farmers' knowledge and capacity to produce quality seeds, promoting the consumption of these crops to national consumers, and linking farmers to outside groups. As a result, over a period of five years three case studies on three different farmer groups showed adoption rates of new varieties of between 20–50% and that they were able to produce approximately 7.5% of the annual demand for quinoa and lupin seed in Ecuador, from a starting point of virtually nothing. The research shows that the added value of a research institution might not be known at the beginning of the intervention, but rather will emerge over time through dialogue and negotiation based on systematic understanding of the context. Therefore, an appropriate stance for external organizations is to begin with an awareness of the existing assets of a specific farmer group and provide options that can be leveraged by local communities.