bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects on Wing Lift and Pitching Moment Due to the Fin of an Aircraft Flying at Supersonic Speeds
Authors: Jones L. B. 
Published: July 2016

Summary:A simple expression is obtained for the lift induced upon a wing by the pressure field of the fin mounted upon the wing in supersonic flow. This expression holds for all fins with sharp edges provided that the wing trailing edge is normal to the free stream and that the Mach lines from the apex of the fin do not intersect the wing leading edge. If the fin has a blunt trailing edge the further restriction that the wing trailing edge is upstream of that of the fin is also required.Results for the induced lift and pitching moment are presented for a delta fin with variations in size and position of the fin relative to the wing trailing edge.
Structural Trends in the Development of Man Powered Aircraft
Authors: Czerwinski W. 
Published: July 2016

In the past few years, man powered flight has become a reality. The remarkable achievements in England by the Hatfield Man Powered Flight Group prove that man may take off and fly with his own muscle power without external aid.Such a possibility seemed very remote to the early pioneers of man powered flight in the late thirties in Germany and Italy. Even after the Second World War, some of the designers of these pre-war aircraft still believed that the take-off of a man powered aircraft would never be possible without some outside assistance.
The Magnification of Roughness Drag by Pressure Gradients
Authors: Nash J. F. , Bradshaw P. 
Published: July 2016

SummaryA simplified analysis indicates that the increase in profile drag of an aerofoil due to an isolated roughness element is, in general, different from the drag of the element measured on a flat plate with the same free-stream velocity. This “magnification” effect is caused chiefly by the effect of the pressure gradients on the boundary layer downstream of the roughness element.The degree of magnification is not closely approximated by the ratio of local to free-stream dynamic pressure and, in many typical cases, the contribution to the drag due to roughness elements may be seriously under-estimated in this way.Measurements of the effect of the initial boundary-layer thickness on the subsequent development of a turbulent boundary-layer in an adverse pressure gradient support the theoretical conclusions.
STOL—Some Possibilities and Limitations
Authors: Mair W. A. 
Published: July 2016

The Ninth Lanchester Memorial Lecture was given by Professor W. A. Mair, MA, FRAeS, on “STOL—Some Possibilities and Limitations” in the Society's Lecture Theatre on 12th May 1966. The Chair was taken by the President, Mr. A. D. Baxter, MEng, CEng, FRAeS. Before the lecture he presented the Society's Gold Medal for 1965 to Professor M. J. Lighthill, DSc, FRS, FRAeS, for “his outstanding original work in many fields of Aeronautics”, explaining that Professor Lighthill had been unable to be present at the Wilbur and Orville Wright Memorial Lecture in December 1965 when the Society's main awards for the year were presented.The President then said that this was the first meeting of the Society since his installation as President and it was a very pleasant way to start his year in office with first, the presentation of the Gold Medal to one distinguished scientist and second, the introduction of another as the Lanchester Memorial Lecturer.There would be many members of the Society who would remember Dr. Lanchester, his attendance at lectures and his contributions to the discussions. It was true, however, that the real stature of such men was rarely recognised at close quarters and often only in the light of later developments was the importance of their work realised. It was 20 years since Dr. Lanchester's death and their Memorial Lecture was in its ninth year. Each year, each President had added a tribute to this great man. He was a man of many parts—a scientist, musician, poet and engineer and aeronautics owed much to him. It was fitting that the Lecture had established a tradition of surveying some field of research associated with aerodynamics, in which Lanchester was so eminent. He thought that Lanchester would approve of both the subjects discussed and the distinguished men who had honoured his memory by presenting them. Before introducing Professor Mair he wished to welcome Mrs. Lanchester and Mr. George Lanchester and his wife, and Mrs. Mair.Professor Mair must be well known to most of them. After graduating in Mechanical Sciences at Cambridge in 1939 he had joined the Royal Aircraft Establishment at Farnborough, where he scent some six years in the Aerodynamics Department doing research on high subsonic speed, both in the wind tunnels and in full-scale flight. In 1946 he had gone to the University of Manchester as Director of the Fluid Motion Laboratory and since 1952 he had held the Francis Mond Chair of Aeronautical Engineering at Cambridge. His chief interest there had been mainly in low speed aerodynamics and his authority in that field was widely recognised. In 1963 he had been appointed Chairman of the Powered Lift Committee of the Aeronautical Research Council.
The U.K. Polaris Project
Authors: Shepherd C. W. H. 
Published: July 2016

I am very happy to have this opportunity to tell you about Polaris, which has had such a tremendous impact on the world situation. It will be appreciated that I cannot divulge anything of a classified nature, and that this places great restriction on what I can say. Nevertheless, I hope that what I can say will be of interest; it will be slanted towards the weapon aspects, as this is my prime responsibility.I will start with some background information on how our programme started and the special measures we found necessary to stand a chance of getting our task completed in the timescale.
Propulsion Controls on the Concorde
Authors: Young Pierre 
Published: July 2016

SummaryOne of the novel problems presented by supersonic transports is the control of the complex powerplants needed to achieve optimum efficiency over a very wide range of forward speeds.The subject is a large one and its proper understanding involves the disciplines of aerodynamics, thermodynamics, servo-theory and finally human engineering, because its end product is a set of knobs, levers, lights and dials which must be usable by the flight crew.This paper is intended as an elementary introduction, using the special case of the Concorde as a basis. First, an attempt is made to give the aerodynamic and thermodynamic reasons for the large number of powerplant variables which the control systems must manipulate. On this basis, a functional specification of the control systems is established and, finally, the crew's job of propulsion management is described step-by-step in the course of a typical mission.
Development and Future Potential of Maraging Steels
Authors: Haynes A. G. 
Published: July 2016

SummaryConventional low-alloy steels at strengths above 100 ton/in2 have been successfully used in various aerospace applications, but laboratory test results, service-performance data and problems in production indicated a need for steels which possessed improved mechanical properties, and which were simpler to machine and fabricate. The 18% Ni-Co-Mo maraging steels were developed in 1961 with the aim of fulfilling this need, and since that date several thousand tons of the steels have been produced and used in all common shapes and forms. In comparison with low-alloy steels of equivalent strength, 18% nickel maraging steels have greater resistance to fracture at highly-stressed notches, defects or cracks, and their susceptibility to hydrogen embrittlement/stress-corrosion failure is generally far superior. The un-notched rotating bend fatigue properties of machined and mar aged specimens of 18% Ni-Co-Mo maraging steels tend to be superior in the low-cycle range and similar in the low-stress range to the properties of low-alloy steels of comparable strength. The fatigue properties of unnotched, in contrast to those of notched, specimens are affected by heat-treatment/machining procedure. Experience gained in production of components has proved that the 18% nickel maraging steels are extremely simple to heat treat, to machine, to cold form and to weld. Exploitation of these advantages can frequently offset the higher initial cost of maraging steel. For example, an analysis of production costs for a complex aircraft component has demonstrated that the use of maraging steel enabled the component to be made by forging and machining at 5-20% lower cost than with a conventional low-alloy steel, despite the fact that initial material costs were five times greater. 18% Ni-Co-Mo maraging steels retain high strength at temperatures up to 350-400°C, and have given good service in short-duration heating cycles at much higher temperatures. Maraging steels may be surface hardened by various methods, and gears and dies treated by simultaneous nitriding and maraging have given excellent performance.The tremendous technological efforts which have been made in the past five years have yielded the majority of data and experience necessary to ensure successful use of the 18% Ni-Co-Mo maraging steels in the aerospace industry.
A New Approach to Airline Economics The Vehicle Millemile (VMM)
Authors: Willis R. W. E. 
Published: July 2016

A Vehicle Millemile is a 1000-mile unit of flight production. A big jet may cost in total £1500 to fly 1000 statute miles or 1 VMM.If 6 tons of passengers (or 60 passengers and their free baggage) earn £200/Paxton Ton-Millemile x 6=£1200, and the revenue from 3 tons of cargo is £100/Load Ton-Millemile x 3=£300, it is simple economics to see that this “mix” will provide breakeven with 9 tons load on board and a total revenue mix of £1200 + £300=£1500/VMM or per 1000 miles. A big jet flying 1600 VMMs per annum at £1500/VMM costs £2.4m and the above passenger and cargo ton factors would provide sufficient revenue to break even.In a few seconds, therefore, we have ascertained the composite “mix” of load and revenue needed to meet the cost of flying the aircraft 1000 miles, and the answers are far more enlightening than saying that an average 60 passengers are carried at 4.8 d/PM and 2721 kg of cargo are carried at 24 d/LTM.The fact that many medium size or small airlines have route stagelengths of less than one Vehicle Millemile at 500 miles or 200 miles makes no difference to the validity of ease of application of VMM Economics, but its great value Jies in the study of intercontinental big jet operations, SST analysis, sub-orbital flight and even interplanetary flight costing.
A Wind Tunnel Investigation of a Thin Aerofoil with a Sharp Leading Edge, and Blowing Applied at the Mid-Chord at Two Angles Relative to the Surface
Authors: Wygnanski I. 
Published: July 2016

SummaryExperiments have been made on a thin two-dimensional aerofoil with sharp leading edge and with a jet blowing through a mid-chord slot on the upper surface in order to control the boundary layer and circulation around it. The measurements were made at low Mach number. The effect of changing the angle of blowing was studied in anticipation that this would help to control the leading edge separation bubble. It transpired that variation of the blowing angle caused little change in lift coefficient but produced an appreciable change in moment coefficient. A low pressure separation bubble was formed downstream of the slot with the jet discharging at an angle and subsequently re-attaching to the surface. This reduced the nose-up pitching moment about the quarter-chord point. The experimental results are in fair agreement with the “jet-flap” and jet entrainment theory.
A Note on the Free Vibrations of Cantilever Plates with Swept-Back Leading Edge
Authors: Kornecki A. , Maimon G. 
Published: July 2016

Free vibrations of triangular and trapezoidal plates have been analysed recently theoretically and experimentally by many authors. Some of them applied the Rayleigh-Ritz procedure, while others proposed to use the Kantorovich-Vlasov method, reducing the problem to solution of an ordinary differential equation.In this note, the method developed in ref. 7 on the basis of Reissner’s modified variational theory is extended to include trapezoidal cantilever plates (Fig. 1).Comparison of theory and experiment shows that, retaining four terms in the deflection function, one obtains three natural frequencies to a high degree of accuracy.
The State of Affairs in Civil Airlines
Authors: Rossiter H. G. 
Published: July 2016

In terms of cost, BEA estimate this to be worth over £3 000 000 a year or, putting it another way, 7% of the revenue we receive has to pay for unreliability.No specific allowance is made for the rectification of defects in the scheduling of aircraft during its turn-round time and to cover this we aim to schedule two stand-by Tridents, two Vanguards, one Comet and three Viscounts for their respective fleet sizes, so that if the snags are anything but minor, the stand-by aircraft take over while the defective one is rectified.
Accessories
Authors: Sturm F. 
Published: July 2016

The Title of this paper presupposes the existence of the most important and fundamental document, namely a clear specification of design requirements.The normal sequence of activities after receipt of the specification is as follows: —
Design.Prototype and Experimental batch manufacture.Development (and Approval Testing).Production.Customers’ Use.The function of Design and Development determines the ability of the design to meet the specification, and this can be classified as the “Quality of Design.”
The Effect of Reliability on the Sortie of a Patrolling Aircraft
Authors: Harvey R. A. 
Published: July 2016

The operational sortie of some military aircraft involves a patrol phase. Typical of these aircraft are Airborne Early Warning (AEW) aircraft, or interceptors operated in a “combat air patrol” mode. For this type of operation, the available endurance on patrol is obviously an important attribute, and in presenting the performance of an aircraft the maximum patrol time as limited by the fuel capacity of the aircraft is usually computed and quoted.However, the overall reliability of a complex modern weapon system is such that the “mean time between failures” (MTBF) is usually not large in comparison with the fuel limited flight time. A significant proportion of flights will therefore be curtailed by failures, which necessitate a premature return to base, rather than the flight continuing to the maximum flight time.
Decision Theory and the Shape of Structures
Authors: Porter Goff R. F. D. 
Published: July 2016

SummaryEngineering structures are usually designed to minimise weight or some other cost criterion, subject to specified loading and functional conditions being met. The techniques of decision theory may be applied if the cost can be described mathematically in terms of the design variables. In particular, dynamic programming may be applicable to designs for which the parameter values can be derived sequentially. Dynamic programming is here introduced to obtain minimum weight layouts for two types of cantilever structure and comparisons are made with known Michell solutions. The results suggest that other near optimum configurations could be systematically derived under conditions less restrictive than those assumed by the Michell theory.
The Electronic Control of Gas Turbine Engines
Authors: Sadler A. , Tweedy S. , Colburn P. J. 
Published: July 2016

The advances made in the development of gas turbine engines during the past two decades have been remarkable. The engines have been improved tremendously in terms of power, weight, efficiency and cost. They are now being applied successfully as the prime movers for helicopters, VTOL aircraft, ground power units and for many other diverse purposes, besides the more conventional military and civil aircraft.There have been parallel advances in the development of gas turbine engine fuel systems (which for convenience may be subdivided into the “control” and the “pumping arrangement”). These systems were originally wholly hydro-mechanical in nature. Sixteen or so years ago, the first supplementary electronic devices were introduced into fuel control systems. Since then, progressively more complex hybrid electronic/hydro-mechanical systems have been employed, with a corresponding easement of the demands on the hydro-mechanical portion. In 1957 Sturrock described to this Society what is now the classic Proteus engine control system used in Britannia aircraft. The satisfactory experience gained with the Proteus system led to the adoption of a comprehensive electronic fuel control system, coupled to a relatively simple fuel pumping system, for the supersonic Olympus engine. This system has been described by Hunt and by Colburn, Tweedy and Dent in papers presented at the joint RAeS/IEE conference “The Importance of Electricity in Aircraft” in 1962. Further papers by Rush presented at the same conference and by Airey in 1963, were devoted to the more general aspects of control.
On Transient Temperatures and Thermal Stresses in an Idealised Wing Structure
Authors: Webber J. P. H. , Houghton D. S. 
Published: July 2016

SummaryAn analytical solution is given for the one-dimensional distribution of temperature in a web of an idealised multi-cell wing structure when the adiabatic wall temperature variation is assumed to be either an instantaneous or a linear function of time. The maximum temperature difference between skin and web centre is computed for a range of structural geometries and thermal parameters. Thermal stresses are calculated assuming a parabolic temperature distribution in the web.
The Maximum Pressure Rise Attainable in Subsonic Diffusers
Authors: Stratford B. S. , Tubbs H. 
Published: July 2016

SummaryAn analysis of experimental results shows that the maximum pressure rise attainable in a two-dimensional subsonic diffuser of length L correlates with the parameter L/δ0*, δ0* being the displacement thickness of the boundary layer at entry. The results agree well with boundary layer theory.
The First Two Years of Operational Experience with the Sikorsky S-61
Authors: Belinn Clarence M. 
Published: July 2016

In the early 1930s, when the 14-passenger DC-2 made its appearance, it was regarded as too big for anything but transcontinental operations, both from the standpoint of capacity and airport requirements. When its follow-on, the 21-passenger DC-3, came along, it sparked a mammoth new Federal Airport Programme, and several regional air carriers in the United States almost choked on red ink. Others merged into systems big enough to absorb this monster.Had someone suggested that within a short span of three decades a helicopter carrying 28 passengers would be hedge-hopping around Southern California, operating day and night from “micro” airports, which we call heliports, I am afraid he would have been given a silent stare.
On the Closed Motion of a Fluid in a Square Cavity
Authors: Mills Ronald D. 
Published: July 2016

SummaryThis paper is concerned with two-dimensional, incompressible fluid motion generated within a square cavity (a) by an outer stream and (b) by the action of a flat surface passing over one of its sides. This type of motion (“cavity flow”) is considered to consist of a boundary layer surrounding an inviscid “core.” A solution of a linearised form of von Mises’ equation is obtained for steady flow in the boundary layer for constant pressure and that of a small periodic variation around the walls of the cavity. From this analysis the vorticity imparted to the core is obtained. The motion in the core is then determined on the basis of the persistence of this value of the vorticity. Experimental results are given for (a) and (b) and compared with the theory. A method of solution of the non-linear boundary layer problem is indicated.
Tools of Airline Management
Authors: Dyment J. T. 
Published: July 2016

Summary:—Competition is too keen to permit Management to continue with methods satisfactory five or ten years ago and some typical modern tools of management are reviewed.The use of Electronic Data processing equipment (EDP) can be overdone but when used wisely it can be of tremendous help in enabling management to fulfil its responsibilities and to make good decisions. Many areas are reviewed where EDP has been used to advantage, including processes used for planning, marketing, maintenance, inventory, finance, personnel and on-line systems such as automatic reservations, teletype switching, etc. Although the examples represent modern airline management techniques they are also usable by many other industries.
Unsteady Air Loads on Helicopter Rotor Blades
Authors: Miller R. H. 
Published: July 2016

An appropriate introduction to the topic of this lecture is the following comment taken from Cierva's third and last lecture presented before this Society in 1935:“Perhaps the most irritating of the secondary difficulties met with in the Autogiro development have been those of a dynamical nature. The dissymmetry of speed on both sides of the rotor produces periodical variations in the lift and drag…“The Fourth Cierva Memorial Lecture, which it is my privilege to present, is concerned with these periodic variations and their contribution to what remains one of the most irritating problems in rotary wing design.
Everyday Air Law
Authors: Martin Peter 
Published: July 2016

From time to time in the course of my practice as a Solicitor I have the privilege of coming into contact with people who are concerned, as designers, engineers, pilots, operators, commercial and technical staff and insurance brokers and underwriters, with the actual business of designing, manufacturing, flying, operating and insuring aircraft.Several of them have said to me that the Air Law Group of the Royal Aeronautical Society would fulfil a useful and worthwhile function, so far as they were concerned, if it would try to give them a basic but overall picture of what “air law” was and how their own day to day actions could be affected by it.
Experiments with a Pitot Rake at M = l·60
Authors: Quincey V. G. , Callinan J. 
Published: July 2016

SummaryTests at a Mach number of 1·60 show clear evidence of interference on the end tubes of a Pitot rake whose adjacent tubes touch. This effect is increased when the rake is made into a solid rectangular slab by the addition of fillets between the tubes. By making the gap between the tubes equal to one tube diameter the interference is almost eliminated.The magnitude of the interference on the end tubes is considerably affected by the ratio of the Pitot orifice to the tube diameter; of the three values of this ratio tested the one close to unity (i.e. a sharp-edged Pitot) was found to have the least interference.
The Production Aspects
Authors: Williams T. O. 
Published: July 2016

The contribution of the production engineer to the improvement of aircraft structures lies in producing better and cheaper aircraft more quickly.In the first place he must advise the structural engineers as to what methods of construction are practicable within the timescale of a particular project. He must also ensure that full weight is given to the economics of production in determining the type of structure to be employed. In this respect he must guard against a tendency to conservatism. It is always easier, and usually cheaper, to do a thing the way it has been done before than to develop something new, but in the long term some structural developments which appeared almost impossible have become routine economic processes.