bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Structural Test Frame with Automatic Loading
Authors: Page F. W. , King J. C. 
Published: August 2016

The Design of test frames of all types owes a great deal to the pioneer work of the Structures Department, Royal Aircraft Establishment. This particular frame contains some novel features and has been subjected to some unusual overall calibration tests, particularly in relation to the entirely automatic and centralised control gear.The choice of apparatus for testing large scale structural components may be influenced by many factors. In the present case, the choice of a test frame rather than other types of equipment was governed by the following considerations.In an industrial establishment it is essential that test equipment should be put to maximum use. Unlike a central testing establishment such as the R.A.E., major strength tests are relatively infrequent and therefore the equipment should also be suitable for as much as possible of the development and research testing which cannot be undertaken on standard material testing machines.
Planning and Aircraft Development
Authors: Olaf Thornton F. 
Published: August 2016

Much has been written about planning and progressing as applied to manufacture, but there is a noticeable lack of information on its application to the design work which must precede construction.It is in order to help fill this gap that the present paper has been written.The paper deals with planning applied to the development of prototype aircraft from the time of submitting a tender up to the first flight of the first prototype.It discusses the methods of estimating the lapsed time up to first flight, the design man-weeks likely to be expended, methods of measuring design progress and the cost of design changes.
French Turbo–Propeller and Turbo–Reaction Engines
Authors: Destival P. 
Published: August 2016

When, in the course of his visit to Paris in May 1948, Dr. Roxbee Cox invited me to lecture to the Royal Aeronautical Society on our work in the field of turbopropeller and turbo-reaction engines, I was torn between two sentiments; the great honour which was done to me, and the seeming temerity for a French engineer to discourse on aircraft turbines before some of the people who had been responsible for the W2 700, the Nene, Ghost, F2, Theseus, Mamba, and other engines. The first of these sentiments however carried the day, as it could hardly fail to do in view of Dr. Roxbee Cox's extreme kindness.Therefore I ask for the indulgence of my audience in listening to this, the first account to be given of the modest work done since 1941 by a team of French technicians, who were specialists in steam and industrial gas turbines, who had foreseen the possible development of the latter for aircraft, and who, completely cut off from the engineering world during the Occupation, at first worked literally in complete isolation, unaware even of the existence of the British and German achievements.
Some Notes on Aircraft Overhaul and Maintenance
Authors: Jackson Clifford H. 
Published: August 2016

Commercial aircraft, in common with all public transport, must be subjected to routine inspections and regularly overhauled in the interest of both safety and economy.Aircraft maintenance and overhaul are not just the domestic concern of the organisation doing the work. There must be adherence to Standards approved by the Air Registration Board on behalf of the Ministry of Civil Aviation; and these Standards are the national interpretation of some of the directives issued by the International Civil Aviation Organisation as part of the international agreements regulating air safety. The regulations are neither rigid nor detailed, but they exist for the protection of air travellers against the remote chance of an operator failing to maintain airworthiness. In particular, they call for regular maintenance checks and, to procure annual reissue of the Certificate of Airworthiness, an annual overhaul or its equivalent.
High–Speed Flying
Authors: Derry John D. 
Published: August 2016

The Title of this paper gives only the broadest indication of the line it is intended to take. Other papers with similar titles have been read by those connected with the design or aerodynamic side, but this paper is mainly concerned in conveying the pilot's own view of the problems of high-speed flying.The paper is divided under the following main headings:—1.The obstacles to negotiate at high and low altitude.2.The approach to high–speed investigation and means of obtaining test results.3.Present and future requirements of research aircraft.4.Pilot safety measures.5.Some requirements of a pilot engaged in high speed research and development flying.For the most part it is intended only to cover research and development flying. This necessarily entails some reference to combat, which is in itself a separate field.The problems confronting a pilot who sets out to explore the behaviour of contemporary aircraft at high speed are considered first.
Power Plants for High–Speed Aircraft
Authors: Baxter A. D. 
Published: August 2016

A few years ago when high–speed aircraft were mentioned, speeds of 300 to 400 m.p.h. came to mind. The advent of jet propulsion has made those figures 100 per cent, out of date and today speeds are discussed more and more in terms of Mach number; for example, high–speed subsonic aircraft fly at Mach numbers of 0.85 to 0.90, aircraft are flying in the transonic region and supersonic guided missiles are proposed for speeds anywhere between M=1.5 and 2.5, i.e. ground level speeds up to 2,000 m.p.h.It is proposed to review very broadly the suitability of propulsion units for these transonic and supersonic applications. What is the difference between ordinary power plants and those for high speed? The answer might be contained in another question—why are supersonic aircraft different from conventional types? The aerodynamicist will give an involved explanation concerned with compressibility, drag rise, shock waves, and so on.
Prophecy and Achievement in Aeronautics
Authors: Garner Harry M. 
Published: August 2016

The Fortieth Wilbur Wright Memorial Lecture, “ Prophecy and Achievement in Aeronautics,” was given by Sir Harry Garner, K.B.E., C.B., M.A., F.R.Ae.S., before the Royal Aeronautical Society on Thursday 29th May 1952 at the Institution of Civil Engineers, Great George Street, S.W.I. Mr. G. H. Dowty, F.R.Ae.S., President of the Society, presided over the meeting which comprised some 350 members and guests.Medals and Prizes awarded by the Council for 1951-1952 were presented before the Lecture.
Research on Aerodynamic Noise From Jets and Associated Problems
Authors: Richards E. J. 
Published: August 2016

SummaryAfter two years research work in the Universities of this country and elsewhere, there is need for a comprehensive review of the present position on the suppression of aerodynamic noise from jet engines. This report outlines the fundamental understanding of the problem that has been achieved, the basic experimental work done, and the noise suppression techniques which have been suggested.A study is made of measured noise levels on advanced types of engines and an analysis is made of reductions required and so far achieved with the proposed noise suppression devices. While the basic principles underlying noise formation, both in subsonic and supersonic jet streams are beginning to be understood, the noise reductions so far achieved are still insufficient and warrant an extended programme of research.The report includes helicopter noise analyses with pressure and pulse jets, and touches on the problem of structural fatigue in the vicinity of a jet stream.
The Flexural Centre or Centre of Shear
Authors: Duncan W. J. 
Published: August 2016

This paper reviews work on the flexural centre of elastic cantilever beams and contains a number of hitherto unpublished results, including a formula giving the position of the flexural centre in terms of the Prandtl torsional stress function.The appearance of the note by Jacobs has prompted the preparation of a review of this subject which is all the more desirable as several of the investigations made shortly before the 1939-45 War were never published and others, although published, seem to be in danger of being overlooked. The present paper contains a number of hitherto unpublished results. The question of nomenclature is worthy of mention since general agreement is lacking. Some of the names used are flexural centre, centre of flexure, elastic centrum and centre of shear but a complete search of the literature would probably lead to the discovery of yet other names. The terms “centre of shear” and “elastic centrum” seem vague and fail to indicate that the point referred to has any special relation to flexure. We shall here use the name “flexural centre” exclusively.
Airframe Fatigue
Authors: L. P. Coombes  
Published: August 2016

The Journal in which Mr. W. Tye's Second Barnwell Lecture has been published (“ The Outlook on Airframe Fatigue,” May 1955 Journal) has now reached Australia. I felt that some comment was called for when I discovered that Mr. Tye had not mentioned the work done in Australia on the life of aircraft structures.What I believe to be the facts are as follows. Australian concern regarding fatigue was awakened in January 1945, when a Stinson air liner VH-UYY crashed with the loss of ten lives. The analysis made by the C.S.I.R. Aeronautical Research Laboratory confirmed that it was caused by a fatigue failure in the welded tube of the primary wing structure.Mr. H. A. Wills, in charge of structural and metallurgical research at the Laboratory, initiated a programme of fatigue tests on actual aircraft wings, designed to give factual answers to the problem of determining the safe life of aircraft structures. The basic idea that this could be done had been suggested in a paper by Bland and Sandorf0, and the Stinson accident provided the necessary urge.
Part 2 Some Features of Flight Testing on the Fairey F.D.2 Leading up to the Successful Attempt on the World Speed Record and Subsequent Flying
Authors: Twiss L. P. 
Published: August 2016

The opening paragraph in my first Flight Test Report after the initial flight of the Fairey Delta 2 still rings very true today:—“This aircraft shews every promise of being a very pleasant flying machine. Soon after take-off, I had confidence in the handling characteristics, and I should like to congratulate all the design and engineering personnel who made this possible.”This great day was the 6th October 1954, at Boscombe Down, and was the start of an intensely interesting development programme—not without its setbacks and excitements—which was highlighted last March by the gaining of the World's Absolute Air Speed Record for Britain. The early flights followed the pattern of most prototype aircraft and, but for an unfortunate setback on the fourteenth flight, went very smoothly.
An Analysis of Flexural Systems under Arbitrary Distortion and End Loading
Authors: Midgley P. J. 
Published: August 2016

SummaryThe effects of end loading on an arbitrarily distorted flexing beam are investigated, with particular reference to bending moment distributions along the span of the beam, and the effects of lengthwise strains. Cross-spring and “ spider ” type flexural systems are treated in detail. Curves are presented which enable the stiffness and stressing of any flexural system to be calculated for any loading conditions, subject only to the restriction that deflections are small, so that the linearised beam equation may be applied.
Solution of Aeroelastic Problems by Means of Influence Coefficients
Authors: Williams D. 
Published: August 2016

SummaryIt is shown that, on the basis of the data provided by two sets of influence coefficients for a wing (or other surface)–an “elastic” set giving deflections (and hence incidence angles) in terms of applied loads, and an aerodynamic set giving aerodynamic loads in terms of incidence angles (or other linear function of the displacements)–all “static” aeroelastic problems can easily and expeditiously be solved by the use of a digital computer. It is also suggested that the same method of approach may well be used for solving oscillatory aeroelastic problems such as flutter.
Thickness Parameters by Rapid Integration of Turbulent Boundary Layer Profiles
Authors: Garner H. C. 
Published: August 2016

The turbulent boundary layer on an aerofoil is represented by simple distributions of velocity, so as to obtain approximate general formulae for the displacement and momentum thicknesses in terms of two ratios of local velocity to that at the edge of the boundary layer.Optimum positions for the local velocity are calculated to be at 0·15 and 0·62 of the boundary layer thickness from the aerofoil surface. The accuracy of the formulae is closely examined. A rapid experimental and numerical procedure is given for estimating the displacement and momentum thicknesses within ± 2 per cent. A minimum of seven velocity measurements has been found satisfactory in practice.
Liquid Propellant Rocket Motors
Authors: Diplock B. R. , Lofts D. L. , Grimston R. A. 
Published: August 2016

It has been said that a rocket motor is the simplest “ prime mover.” This is correct in theory, since fundamentally a rocket consists of a chamber containing a gas under pressure, having a nozzle at one end through which the gas expands, forming a propulsive jet. Since the pressure ratio of the rocket is always greater than the critical pressure ratio, the nozzle is invariably of the convergent-divergent or de Laval type in which the velocity is subsonic up to the throat, sonic at the throat and supersonic in the divergent portion.It is a popular fallacy that a rocket or jet engine obtains a forward thrust by allowing the rearward jet of gas to push against the atmosphere in which it is operating. This is not correct and it can be proved that a rocket will operate successfully, and more efficiently, in a vacuum.
Tube of Least Weight for Given Torsional Stiffness
Authors: Howard H. B. 
Published: August 2016

Consider a thin-walled tube fixed at one end and subject to torque of known distribution. The problem is to find how the thickness of the wall should vary along the length so that the weight is a minimum for a given angle of twist at the free end.At distance x from the fixed end, let T be the applied torque, A the enclosed area of the tube, P its perimeter and y the wall thickness.
Reheat for Gas Turbines
Authors: Edwards J. L. 
Published: August 2016

Some five years ago the author was privileged to deliver a Section Lecture to the Royal Aeronautical Society on the subject of reheat. The present paper attempts to summarise the problems which now arise and to give some idea of the progress which has been made in the intervening years.In 1949, reheat was in its infancy in Great Britain. A certain amount of progress had been made in the United States but the information from that source was scanty and vague. Tests at the National Gas Turbine Establishment (N.G.T.E.) had given some engine data but this was in the nature of preliminary information only and was by no means complete. In fact the majority of the problems which now beset us were then completely unknown or were considered unimportant. The N.G.T.E. work was valuable, however, in that it demonstrated the practicability of reheat, although at the time the comments of many who saw this and other schemes in operation were somewhat sceptical and definitely unflattering.
Indicial Admittances for Linear Systems with Variable Coefficients
Authors: Duncan W. J. 
Published: August 2016

The solution of a set of m ordinary linear differential equations of the nth order having variable coefficients can be provided by the use of a set of m2 indicial admittances and the solution is derived from that given by the use of impulsive admittances. The indicial admittances are easily derived from the impulsive admittances and vice versa.An “indicial admittance” is a function representing the response of a system to an applied “input” in the form of a “unit step function” and the concept is due to Heaviside. When the indicial admittance is known, the response to an input which varies with time in an arbitrary manner can easily be found. Similarly, the response can easily be found when the “impulsive admittance” is known, where this is the response to a unit instantaneous impulsive input.
Integral Construction
Authors: Keen E. D. 
Published: August 2016

There has been considerable activity of recent years, particularly in America, in the field of integral structures for aircraft.The fundamental problem in aircraft structures is to make a relatively thin skin covering take applied compression, shear and bending loads. This has been achieved so far by the attachment of stiffeners, but this requires a large amount of riveting which in itself causes structural inefficiency and also spoils the smoothness of the skin, particularly when laminar flow is desired. Metal gluing shows great advantages over riveting in this respect but it is doubtful whether the bond strength will be great enough to attach very heavy stringers to very thick sheet. Where structural loadings become higher the required thickness of sheet and stringers may make the continued use of riveting difficult, if not impossible.
Some Measurements of Leading Edge Separation Bubbles on a 10 per cent Thick Symmetrical Aerofoil
Authors: Black J. , Hunt R. D. 
Published: August 2016

Pressure Distribution and liquid-film tests on a 10 per cent, thick aerofoil revealed the presence of separation “bubbles” close to the leading edge. These bubbles are formed beneath the boundary layer which separates near the leading edge and re-attaches farther aft; their existence is usually indicated by localised constant-pressure regions in the pressure distributions. It is also believed that if a thin film of liquid (such as a suspension of lamp-black in paraffin) is spread on the surface, the scrubbing action of the air rotating in the bubble will tend to draw liquid forward into the bubble, and hence the location and extent of the bubble may be indicated approximately by the accumulation of the fluid.Many boundary layer traverses of bubbles on N.A.C.A. aerofoils have been made, but it was felt that similar measurements of the bubbles on this particular aerofoil would provide useful data, since the separation characteristics of this section appeared to differ from those in the N.A.C.A. tests.
Results of Photoelastic Investigation of Stresses in a Tension Bar with Unfilled Hole
Authors: Jessop H. T. , Snell C. , Jones I. 
Published: August 2016

Although this problem is one which has been investigated by many photoelasticians, there appears to be no record of any systematic exploration of the effect upon the stress distribution of the ratio of hole–diameter to width of bar.In this investigation tests were made upon a standard sized bar with four different sizes of holes, and the stress distribution on the cross section of the bar through the hole centre was explored for the four cases.
Some Thoughts on Aeronautical Research and Design
Authors: Morgan M. B. 
Published: August 2016

“To know, can only wonder breede,And not to know, is wonders seede.”There is a peculiar magic in these lines of Sidney Godolphin, penned 300 years ago. I can think of no better introduction to a paper on aeronautical research and design.Flying is rather a remarkable business, about which we are inclined to get a little blasé nowadays. Few things can tax the engineers' skill more than the design of a modern high performance aeroplane. In its way it represents supremacy in engineering achievement. Let us not take all this too much for granted; and let us remember those gifted designers—no longer with us— who laid the foundations of the art. Among these, the name of Roy Chadwick stands high.
Electronic Control Techniques in Aircraft Manufacture
Authors: Kermack G. S. , Ogden H. 
Published: August 2016

This paper is concerned with a method of improving the utilisation of metal cutting machine tools and thus deals with that part of production covered by machining. It is particularly applicable to the Aircraft Industry, where the production of military aeroplanes must be as rapid as possible and the costs of civil aircraft in a competitive market must be kept to the minimum. As it is designed to be used in conjunction with small quantity manufacture it can be of great assistance in development work.The limitation to the rate at which machining of any part can take place is generally dictated by the rate at which information can be transferred to a machine tool and converted into appropriate slide movements. In large scale manufacture where batch sizes are high, this transfer of information is normally effected by elaborate pre-set tooling arrangements and the cost and time required to prepare this information is acceptable only as the cost per part becomes very small.
Metals and their Heat Treatment
Authors: Williams S. G. 
Published: August 2016

Mr. Williams remarked that the modern tendency in engineering is to endeavour to heat-treat the existing metals to enable them to withstand the stresses induced by modern design.Many similar metals are used as in days gone by, but the modern steels are alloyed with other elements to enable them, with particular treatment, to give much higher strength results. For these alloy steels and also for the lighter alloys, special precautions have to be observed in their manufacture, whether they are destined for automobile or aeronautical work, although with aircraft work more precautions are necessary than in any other class of manufacture.
Part II. Design of Airscrews for Schneider Trophy Race 1927
Authors: Ralli P. A. 
Published: August 2016

Racing airscrews differ essentially from Service or commercial types by reason of the extreme values of engine horse-power, revolutions and forward speed which enter into the specified requirements.These three variables, associated with the condition that the thrust–horsepower shall be a maximum, determine the airscrew completely, but the exceptional values which they assume for racing aircraft have various important reactions on the efficiency obtainable.Thus high power and revolutions, especially the latter, have a distinctly detrimental effect, whereas high forward speed contributes to a large extent to restore the position.I propose to examine very briefly the relative importance of these factors and to indicate how they influenced the process of selection and design in the particular conditions of last year's race.Let us first consider a typical power curve (Fig. I). As it is not permissible at this stage to publish actual figures in detail I have made use of relative scales which should be sufficient for our purpose.
The Machinery Installation of Airship R.101
Authors: Cave-Browne-Cave T. R. 
Published: August 2016

This was a joint meeting of the Royal Aeronautical Society and the Institution of Automobile Engineers, and was held in the Lecture Hall of the Royal Society of Arts, John Street, Adelphi, W.C.2, on Thursday, November 8th, 1928.The President : He extended a hearty welcome to all present and particularly to the new President of the Institution of Automobile Engineers (Mr. L. H. Hounsfield), whom he hoped would attend many future meetings of the Society as well as the joint meetings which had been arranged. The joint meetings had been very successful indeed in the past and he hoped that, in addition to those which had already been arranged for the present session, there would be many others in future sessions.