bluuebunny/crossref_metadata_2025_split huggingface dataset:
Part V: Steady and oscillatory aerofoil-spoiler-flap characteristics
Authors: Tou H. B. , Hancock G. J. 
Published: July 2016

SummaryAn inviscid model for a steady two-dimensional aerofoil-spoiler at low speeds is applied to an aerofoil-spoiler-plain flap configuration. The model is extended to an aerofoil-spoiler-slotted flap configuration. The flow through a slotted flap can result in either attached flow or separated flow about the flap. The location of the separation point on the flap has to be assumed, it is taken empirically to fit experimental data. The inviscid model is extended to the aerofoil-spoiler-slotted flap configuration with the spoiler oscillating in small amplitude simple harmonic motion about a mean spoiler angle. Although both the steady and unsteady models for the aerofoil-spoiler-flap configuration are crude, the results look encouraging.
The View of a Constructor's Pilot
Authors: Baker P. P. 
Published: July 2016

This subject, even as it applies to those areas which are the direct or partial responsibility of the test pilot, is a comprehensive one, and it is not intended to embrace it completely. Specifically this paper will touch only on the area in which the pilot is principally involved. Further, it is not the intention to catalogue the tests required for certification or to describe all of them in detail, but rather to discuss the whole certification process in more general terms.The purpose of Certification is to establish a minimum safety standard, but when forming that standard, sight cannot be lost of the feasibility of achieving it, both practically and commercially. Inevitably, therefore, the discussions or arguments that arise over establishing the standards against which aircraft are going to be assessed must centre around the problem of where the balance between safety and cost should be struck. As previously implied, absolute safety is not only probably impossible to achieve, but quite clearly commercially impractical. The constructor's task must be, therefore, a process of resolving the often conflicting ideas of the various bodies and agencies that attempt to define the “balance” and within that definition offer a commercially attractive aircraft. If he strays widely from the prevailing definition, even in the interests of increased safety, he is in danger of pricing himself out of business. This fact is rather obvious, but no excuse is given for stating it since it is thought to be so fundamental to the subject under discussion, and one that is often overlooked, particularly perhaps by those who are not so involved with the day-to-day operation of aircraft.
Engine Performance Monitoring—Application to Small Fleets and Short-Haul Operation
Authors: Hope J. , Kenworthy K. 
Published: July 2016

Although the title of this paper, for brevity, refers to engine performance monitoring, in fact we mean performance and condition monitoring. In presenting such a paper with particular emphasis on the problems that arise for the Operator with relatively small aircraft fleets operating in the main over short stages, although the comments we have to make are based on TAA experience, a similar situation must exist for any operator with a multiplicity of aircraft types and relatively small numbers of each.We refer to performance and condition monitoring to define the complete task, as it is essential to correlate performance parameters to condition evidence such as vibration level or lubricant deterioration status to obtain a useful perspective.
Self-Aligning Hot-Wire Probe
Authors: Bond A. D. , Porter A. M. 
Published: July 2016

Summary:—This note describes how a single constant temperature hot wire may be used for measurements of direction, velocity and turbulence in a two-dimensional flow. The wire probe is rotated by a servo motor which automatically sets the wire with its axis either in the stream direction or normal to the flow. The accuracy of setting the wire in the direction of the stream is about , and across the stream is about 1°. If the higher accuracy is demanded the velocity and turbulence measurements require a second setting of the probe, at 90° to the previous one. When less precision is acceptable, the angle, velocity and turbulence measurements may be taken at the single setting, normal to the stream.
The Application of Lifting Line Theory to an Upright Bermudan Mainsail
Authors: Tanner T. 
Published: July 2016

SummaryUsing Glauert's analysis and taking into account the restraint due to the surface of the sea, lifting line theory is applied to calculate the distribution of loading, downwash velocity and vortex drag of a “Finn” dinghy's sail when upright. It appears that the loading can probably be represented with sufficient accuracy byI=I0(sin θ+sin 2θ)where k is largely dependent on the apparent twist in the sail and has a value generally of the order of 0-5, that the apparent twist may not be twist at all in the aerodynamic sense, and that the vortex drag is considerably greater than it would be if it were possible to make a sail to give elliptic loading.
On the Definition of “Cooling Losses” in Cooled Gas Turbines
Authors: Ogale V. A. , Jaspers B. W. 
Published: July 2016

In the analysis of cooled gas turbine cycles, the quantity of heat removed by the coolant is termed as “cooling loss”. In the literature, these cooling losses are accounted for by the use of either(a) Cooling Loss Factor, or(b) Cooling Number.Brown defines Cooling Loss Factor (CLF) as a ratio of heat removed by coolant per unit time divided by the total turbine output per unit time.Traupel defines the Cooling Number (CN) as the ratio of heat loss to isentropic enthalpy drop.Cohen and Martin use the CLF in their analyses and May uses the CN.It is the purpose of this note to give a simple correlation of the two and to suggest a new definition to account for these losses.
Compounded Normal Modes of Free Vibration of Cantilever Plates
Authors: Kirk C. L. 
Published: July 2016

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 modesm/n±n/mfor 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 modesm/n±n/mhave discrete frequencies.
National Aerospace Planning
Authors: Caplan H. 
Published: July 2016

Summary:—There is no doubt of the need for strong central planning of aeronautical research and development as advocated by the Post-Plowden Working Party of the Royal Aeronautical Society (pp. 391-392 June 1967 “Journal“).But there are many other problems in the efficient use of aerospace resources which are equally in need of attention by the Society. Among the most important are:
The complementary role of improved industrial and project management.The need to deal separately with the distinct problems of Defence, Civil Aviation and Space—in particular the improvement of Defence procurement methods.The need to discover the correct commercial and engineering bases (as distinct from political bases) for European collaboration.The need to complement the work of a strong planning organisation by providing facilities for high-level and informed technical debate, wherever possible in public.
Engine Development and Manufacture in Sweden
Authors: Gudmundson Gustaf 
Published: July 2016

From the very start of aviation a suitable engine has been the basic pre-requisite for successful flight.The first known Swedish proposal for a heavier-than-air flying machine was made in 1716 by the scientist and philosopher Emanuel Swedenborg. A steam engine, invented by him in 1714, was to provide the propulsion. His superior, “Royal Mechanicus” Christoffer Polhem, opposed the idea, and the project was abandoned without any attempt being made. More than 150 years later, in 1877, another Swede—Carl Rickard Nyberg, well-known inventor of the blow-lamp and other gas-producing devices using liquid fuel—presented a design for a helicopter and 20 years later still, for a steam-engine-driven aeroplane. The engine weight problem was to be solved by using a light tubular steam boiler, invented by him. Several prototypes were produced during the years 1899 to 1910 without being really flyable since the steam engine gave only 10 hp compared with the estimated 40 hp required.
Application of Film Cooling Theory to the Cooling of Aircraft Gas Turbine Chambers
Authors: Sturgess G. J. 
Published: July 2016

SummaryFilm cooling performance expressed in the terms of film effectiveness, is divided into initial and final regions containing respectively, the potential core and transition lengths and, the main decay region. The theory of Kutateladze and Leont'ev, which is representative of present approaches, is presented and shown not to apply to the film initial region. To resolve the questions, what is the minimum acceptable value of effectiveness in a given situation, and, what proportion of the resulting maximum permissible cooled distance is initial region, the film cooling of a hypothetical turbojet engine to power a Mach 2-2 cruise supersonic air liner is examined. Experimental data from cooling devices representative of current European practice are used in the analysis to give realistic results.
The Use of a Digital Computer for On-Line Control of a Jet Engine
Authors: Eccles E. S. 
Published: July 2016

SummarySome of the unusual factors influencing the choice of digital computer control systems for jet engines are discussed first. The conditions differ in various practical respects from conventional process control applications. Having several identical plants in a typical aircraft and the need for flexibility to keep pace with engine development are of particular importance. Approaching digital control with the traditional process control background may be restrictive in selecting potential applications for the technique.Techniques which can be used with computers to simplify and speed up three aspects of the realisation of a practical system are described briefly. The first of these is the measurement of the actual plant characteristics needed in the analysis of the control system requirements. The second is a method of obtaining good response in the synthesis of a non-linear control function. The third is a technique for programme writing and for simulation used in the verification of the control system behaviour.The techniques described are not in themselves necessarily confined to use with digital control systems and should have value in general use.
Centre-Body Nozzles for Supersonic Transport Aircraft
Authors: Herbert M. V. 
Published: July 2016

SummaryIn a supersonic transport aircraft, the propelling nozzle is required to operate at high efficiency over a wide range of conditions — typically a five to ten-fold variation of exhaust pressure ratio. This paper offers some discussion around the problems of geometry which such requirements entail, and explains the reasons for which a nozzle of centre-body form with parallel outer shroud appears an attractive solution. In support of the claims for this arrangement of nozzle, test data are presented from both single and twin models under representative conditions of external flow. (The tests were made at the National Gas Turbine Establishment between 1960 and 1965.)
Torsional Stress Concentration Factors for Grooved Shafts
Authors: Rushton K. R. 
Published: July 2016

SummaryThis paper describes a preliminary investigation of the torsional stress concentration factors for circular shafts containing grooves determined using an analogue computer. The range covered by this analysis is for grooves which increase in depth from a minimum of 0·05 of the diameter of the shaft, with radii which vary from 0·5 to 0·05 of the diameter at the minimum section. Results are presented in the form of a data sheet, and a comparison is made with the approximate expression of Neuber. An investigation is also made of the modifications to the stress concentration factor if the flank is not perpendicular to the centre-line of the shaft.
A Note on the “Isentropic Ramp” Intake Diffuser in the Mach Number Range 6 to 10
Authors: Bergstrom E. R. 
Published: July 2016

A need exists for empirical criteria by which the behaviour of hypersonic boundary layers flowing in adverse pressure gradients can be predicted, thereby placing the design of high Mach number intake/diffuser systems on a rational basis.The main results of the inviscid flow performance analysis of a two-dimensional “isentropic ramp” intake diffusing to supersonic Mach numbers over the free stream Mach number range 6 to 10 are presented. Limitations on the degree of diffusion, and hence geometry, have been deduced in terms of the combustion length requirements of an idealised hydrogen/air combustion process with com-bustor inlet conditions given by the intake. The analysis can be considered as a first order approximation defining the ranges of continuous pressure gradients and oblique shock wave strengths relevant to the experimental investigation of boundary layer flow in the mixed adverse pressure gradients associated with hypersonic intakes.
Recent Developments in Titanium
Authors: Shaw H. W. 
Published: July 2016

The intention in presenting this paper is to outline the main trends in recent alloy development and to indicate the current state of the art as far as the user is concerned, particularly on the behaviour of the new products in the problem areas so designated by the engineering metallurgists and materials specialists in the industry.In reviewing recent alloy development it is convenient to identify two main lines in terms of the metallurgical structures involved, since these tend to define the more appropriate areas for design interest.
Low Speed Handling with Special Reference to the Super Stall
Authors: Trubshaw E. B. 
Published: July 2016

The title of this paper was chosen some time ago. In view of events experienced over the past three years on some modern civil jet transports, I propose to devote the time available to the subject of stall characteristics, together with some of the associated problems and with the methods of solution.Before anyone else raises the point, I wish to point out that the term “Super Stall” is nothing more than popular jargon and is equally as objectionable to the purists as “Deep Stall” or “Stable Stall”. It will, I hope, become clearer later as to what particular characteristics these terms apply.
Aircraft
Authors: James D. 
Published: July 2016

An Examination of the available data on aircraft unreliability, whether on civil or military aircraft shows quite clearly that the systems engineering is more troublesome than the structural engineering.The statistics show that landing gear, brakes, hydraulics, fuel and air conditioning systems are all at fault to approximately the same degree. In addition equipments for which the airframe manufacturer is not directly responsible, are a frequent cause of trouble.The aircraft manufacturers’ contribution to improving reliability must come from three directions.
Contracting in the Civil Fields—The Influence of Competition
Authors: Beverley E. L. 
Published: July 2016

Three of the tenets of a Contracts Manager are (a) that he should not be seen, (b) he only speaks if spoken to, and (c) he ensures that every answer he gives is capable of being interpreted in three different ways. You can imagine, then, how embarrassing it is for me to make what is supposed to be a forthright statement to an audience which I imagine contains a number of customers and potential customers.I suppose one of the most ulcer-making things that can happen to an airline management is to see a piece of brand new and expensive aircraft machinery sitting on the tarmac unserviceable. With the increasing cost of civil aircraft, profits can only be made by keeping them in the air at a high degree of utilisation.
Is the Aeronautical Industry Making the Best Use of its Graduates? A Discussion
Authors: Lickley R. L. 
Published: July 2016

Summary:—The question, as phrased, suggests there is an optimum method of using graduates; this in turn suggests that all graduates have untapped resources and are ready to learn all that can be put before them.In my view, it can always be said of any industry that it does not make the best use of any specific grade of labour; good managements, of course, make much more effective use of their labour force than the bad ones.Graduates vary tremendously in previous training, from say, a mathematics graduate straight from school and college, to a specialist aeronautical graduate with works experience in addition.
The Measurement of Peak Strain
Authors: Howard H. B. 
Published: July 2016

SummaryIt is shown that, in regions near peak strains, improved accuracy of measurement with a strain gauge or extensometer, can be obtained by taking readings over more than one distance including each point. A better estimate of the true strain can then be derived than will be given by a single reading. Peak errors in the region of 8 to 10 per cent can thus be reduced to 1 or 2 percent.Two methods are described: one in which measurements are made at equal intervals along a line, keeping the gauge length constant; the other using different gauge lengths centred on the point concerned, the latter being suitable where a grid can be marked on the surface.
Structural Design of the X-15
Authors: Schleicher R. L. 
Published: July 2016

The 1346th Lecture to be delivered before the Society, “Structural Design of the X-15”, by Dr. R. L. Schleicher, was given on 18th April 1963 in the Society's Lecture Theatre with Mr. B. S. Shenstone, M.A.Sc, F.R.Ae.S., F.A.I.A.A., F.C.A.S.L, in the Chair. Introducing the lecturer, Mr. Shenstone said that Dr. Schleicher was Manager, Structures Engineering, at the Los Angeles Division of North American Aviation, Inc., and he had been with the firm since its inception in 1934. Dr. Schleicher was a graduate of Villanova University and held a degree of B.S. in M.E., and his D.Sc. had been conferred on him in 1957. He had nearly 34 years experience in aircraft structures engineering beginning in 1929. He had been Chief Structures Engineer at North American Aviation, Inc. on all the aircraft designed and built by the Los Angeles Division of that company and that included the X-15. He was a member of the Society for Experimental Stress Analysis and an Associate Fellow of the A.I.A.A. From 1943 to 1958 he had been a member of a number of NACA (now NASA) Committees and Sub-committees and had written a number of technical papers. He was currently serving on an Advisory Committee on Aircraft Structures for the U.S. Air Forces.They were indeed grateful to Dr. Schleicher for coming all this way to lecture.
Flexural Vibration of Rectangular Plates with Stiffeners Parallel to the Edges
Authors: Mahalingam S. 
Published: July 2016

SummaryThe basis of the procedure described in the paper is the replacement of the stiffeners by an approximately equivalent system of line springs. One of two methods may then be used to determine the natural frequencies. A rectangular plate with edge stiffeners, point-supported at the four corners, is used to demonstrate the application of the Rayleigh-Ritz method. Numerical results obtained are compared with known approximate solutions based on finite difference equations. A Holzer-type iteration is employed in the case of a plate with parallel stiffeners, where the two edges perpendicular to the stiffeners are simply supported, the other two edges having any combination of conditions.
The Progress of European Air Transport 1946–1961 with Particular Reference to B.E.A.
Authors:   Lord Douglas of Kirtleside
Published: July 2016

I count it a great honour to have been asked by the Royal Aeronautical Society to deliver the Seventeenth British Commonwealth Lecture. Reading down the list of previous performers in this rôle one feels that it is indeed an election to a very select company.
I have chosen as my subject for this lecture the post-war progress of air transport in Europe. The title may sound rather pedestrian, but I have two main reasons for choosing this theme. First there is the personal reason. I have been intimately associated with the development of air transport in Europe during the post-war period and I am very pleased to have an opportunity to set down a record of the developments which have taken place during those years. Moreover, my associations with European air transport go back to its very beginnings, as pilot of one of Europe’s—and the world’s—first scheduled air services in 1919. The second reason is broader. I welcome an opportunity to review the post-war progress of air transport in Europe because I think that this will show what a revolutionary change the industry has undergone within the relatively short space of fifteen years.
Rectilinear Flight in a Non-Uniform Atmosphere
Authors: Annenberg R. H. W. 
Published: July 2016

The equations showing how to correct for the effect of non-uniformity of the Atmosphere when computing the angle-of-climb (or descent) are well known and can be found in Refs. 1 and 2.From Ref. 1, a climb at constant Mach number M implies a factor F on the Aircraft Weight to give the true angle-of-climbs (in our units for R) given by the expression
The State of the Art in Management Education Applicable to Aerospace Activities
Authors: East F. H. 
Published: July 2016

The Aviation Group of the Ministry of Technology (formerly the Ministry of Aviation) is responsible for spending a large part of the country's defence budget, both in research and development on the one hand and production or procurement on the other. In addition, it has responsibilities in many non-defence fields, mainly, but not exclusively, in aerospace.Few developments have been carried out entirely within the Ministry's own Establishments; almost all have required continuous co-operation between the Ministry and Industry. In the past the methods of management and collaboration and the relative responsibilities of the Ministry and Industry have varied with time, with the type of equipment to be developed, with the size of the development project and so on. But over the past ten years there has been a growing awareness of the need to put some system into the complex business of translating a requirement into a specification and a specification into a product within reasonable bounds of time and cost.
Aero-marine design and flying qualities of floatplanes and flying-boats
Authors: Stinton Darrol 
Published: July 2016

Quite by chance after this lecture had been written I saw at first hand part of the fire-fighting operation in the Tanneron in the South of France using flying-boats. This provided an excellent point from which to begin.On 23rd August 1986 a vast fire was started deliberately, it was alleged, in the valley of the River Siagne, between Grasse and Mandelieu. There was a strong mistral blowing at the time. It was brought under control two days later with the aid of a small force of around nine ‘Pelicans’: Canadair CL-215 flying-boats (Plate 1). Each aeroplane can scoop up over 5000 litres (more than five tons) of water, in 10 seconds while planing at 70 knots (Plate 2). At times three aircraft would land in loose formation to do so. In the end the fire, said to be the worst since 1706, was reported to have destroyed 10 000 hectares (say 25 000 acres) of farm, forest and homes. Four people died, 700 suffered from burns and asphyxia, 8000 were left homeless.