Aeronautical Problems Research Articles

Wellington Airport: A Recurrent Problem in Decision Making

rT HE aerial approach to Wellington International Airport is topographically exciting. One is strikingly aware of the juxtaposition of mountains and hills, bays and coves, and roiled coastal waters, all in close proximity (Fig. i). Rough slopes partially covered with tiered residences and other buildings, roads and tunnels, and shipping and port functions emerge. One element not apparent in this landscape is flat land. Evans Bay to the north and Lyall Bay to the south provide narrow slots for aeronautical approaches; high terrain necessitates slight deviation from a straight-in approach. The airport's single north-south runway crosses the narrow, hilly isthmus of Rongotai at right angles. Wellington International Airport is controversial. Although its aeronautical and geographical problems are evident to an observer, not so apparent from the air or from the ground are the economic and political problems that have recurrently characterized its development. Decisions on airport upgrading, closure, relocation, twin locations, reconstruction, and so forth have challenged Wellington City and Dominion government officials since the airport was opened in 1929. Wellington's location predetermines its importance as the hub of New Zealand's transport system (Fig. 2). The airport, at the southern end of the North Island, is a national and international

Paper 9: Velocity and Rate of Flow Measurements in Internal Combustion Engines

Measurement of both the mean and instantaneous values of gas velocity in internal combustion (i.c.) engines presents problems of considerable difficulty and the application of electronic methods of measurement has made important contributions in this field. The problems encountered in metering pulsating flows are briefly discussed with special reference to the advantages of two metering devices which employ electronic circuits.Whilst pressure transducers enable the variation in instantaneous gas velocities to be inferred in certain circumstances there are many other cases where a direct indication of velocity variation is desirable. The hot wire anemometer (h.w.a.) has been highly developed for aeronautical engineering applications but special problems arise in the reciprocating engine where velocity variations can be large. This paper describes a constant temperature h.w.a. using a d.c. circuit which has proved stable and relatively easy to operate. If velocity measurements in the engine cylinder are required the problem becomes a three-dimensional one, and the response of the h.w.a. to variation in flow direction is discussed. Consideration is given to materials suitable for probe wires.

The Part Played by Wind Tunnels in Modern Aeronautics

Summary:The wind tunnel has been the main instrument for experimental research in aeronautics since the turn of the century and its history is as brief as powered flight itself. It has always played a leading rdle in aeronautics right from the time of the Wright Brothers to the present day.The early form of wind tunnels as developed at the National Physical Laboratory and other research establishments have been replaced over the years by larger and more elaborate facilities, each having a particular speed range and specific role in aeronautical research and development. Modern wind tunnels having continuous operation of the type installed at the Royal Aircraft Establishment involve powers of up to 100 000 h.p. and cost in the neighbourhood of £10 000 000. In spite of this cost it is a sobering thought that, if anything, the overall cost of each data point is less today than it was in the early days of aeronautics. Such tunnels are highly complex instruments for research and development and although they play a rôle similar in many respects to that of a computer, they have the advantage of always dealing with a real fluid. Indeed no known computer could cope with the range of problems that can be solved in a wind tunnel, ranging from such complex problems as the structure of turbulent flow to the pressures in separated flow regimes, to quote just two examples. This fact must always be kept in perspective when arguments are presented for more and more work on digital computers to solve basic fluid motion problems. Of course we cannot overlook the problems of interpretation of wind tunnel data and the difficulties encountered in extrapolating these data to flight conditions.The development of theories for such problems together with answers is of ever increasing importance, especially as the problems in aeronautics are becoming more and more complex. These solutions have the important function not only of high-lighting certain aspects of the flow, but of pin-pointing the important parameters in a problem together with providing better than order of magnitude results. However, theories must be based on physical facts and these can only be determined in the final analysis from experiments.The wind tunnel has three highly significant roles in modern aeronautics:(i) Experimental research as a forerunner to future theoretical research.(ii) Experimental research as a confirmation and extension of theory.(iii) Current research and development work on a given aircraft.The current trend in bringing strong theoretical and experimental groups together, plus the employment of rapid measurement techniques in wind tunnels, promises the greatest possible productive utilisation of these highly important and expensive facilities. In most cases today they are playing a strong, if not the leading, role in aeronautical development.

Heat and Mass Transfer in Aeronautical Engineering

SummaryThe main purpose of the paper is to show that standard techniques of heat and mass transfer theory, as practised in other branches of engineering, can be helpfully applied to the corresponding aeronautical problems, particularly those arising in connection with high-speed flight and rocket propulsion.

Time Series Problems in Aeronautics*

Abstract This paper reviews some recent applications of random process theory to problems in aeronautical engineering. A number of random type disturbances that cause aeronautical problems are described and some of their effects on the airplane indicated. Particular attention is given to the effects of atmospheric turbulence in giving rise to airplane loads and structural stresses. The general approach used in calculating airplane responses to random disturbances by means of power spectra techniques is then described. As a concrete illustration, some results obtained in a study of missile behavior in rough-air flight are presented. An effort is also made to indicate some unsolved statistical problems that are encountered in these applications.

Time Series Problems in Aeronautics

Time Series Problems in Aeronautics

Tribute to a Pioneer

TO those who have grown up with aeronautics the name of General Crocco is almost a legendary one, and he is in historical fact contemporary with the Wright Brothers since his investigations into the subject date from the very beginnings of the century, as is evidenced by the fact that he took out his first patent on the control of aeroplanes in 1903. He followed this in the ensuing year with a famous paper on the stability of airships read before the Academie des Sciences, and one on the theory of aeroplane flight; while the catholicity of his early interests is further shown by his association with Ricaldoni in a series of experiments with airscrews mounted on a hydroplane, for the construction of which he was partially responsible, on Lake.Bracciano in 1907. When it is recalled that in 1906 he was concerning himself with the phenomena of auto‐rotation in connexion with helicopters, the breadth of his out‐look on aeronautical problems, and his astonishing prevision, is manifest. For many years he was, of course, chiefly known for his association with a series of ingeniously designed semi‐rigid airships produced by the Italian Government, but his interest in heavier‐than‐air flight throughout his career found outlet in innumerable articles. In recent years he has been particularly associated with the allied phenomena of stratospheric and supersonic flight; as witness his paper entitled ‘Flying in the Stratosphere’, which we had the privilege of publishing in Aircraft Engineering in July 1932.

The Gyroscope and its Applications

THE applications of the gyroscope to marine and aeronautical problems during the Second World War have been so many that pre-war treatises have become out of date. This book is an endeavour to bring the subject up to date, with a minimum amount of mathematics. The subject is considered in three sections, each by a different author. The first section deals with the simple theory of the gyroscope, and with its main properties; appendixes are concerned, chiefly, with the errors of the gyroscopic compass. The second and third sections treat of the marine and aeronautical applications respectively, and each is self-complete. Since much of the material of these two sections is new and practical, they are of more interest than the first; they contain scarcely any mathematics; they are illustrated by excellent diagrams and photographs, and make exceedingly interesting, though very technical and at times difficult, reading. The Gyroscope and its Applications Edited By Dr. Martin Davidson. Section 1: General Theory, by Dr. M. Davidson; Section 2: Marine Applications, G. C. Saul; Section 3: Aeronautical Applications, by J. A. Wells and A. P. Glenny. Pp. 256. (Lodon: Hutchinson's Scientific and Technical Publications, 1946.) 21s. net.

An Elementary Study of the Spin

In this paper a comprehensive survey of spinning phenomena is attempted. The presentation is elementary in character, starting with the simple geometry of the spin, then dealing with autorotation, including wing‐dropping tendencies, passing on then to a consideration of aerodynamic pitching and yawing moments, and finally some attention is given in turn to the incipient spin, the steady spin and recovery. The arguments are in the main qualitative so that a student of the subject may first familiarise himself with the fundamental principles. A bibliography is given which includes all the important papers published on the subject within the last few years, together with a few which are now more of historical interest. Most of these reports emanate from the A.R.C. and N.A.C.A. and due acknowledgment is made of the source of some of the experiments which have been taken in illustration of the points made. Although not the urgent problem that it once was, the subject of the spinning of aeroplanes continues to occupy a prominent place in the programmes of various research establishments, both here and abroad. Because both of the complexity of the phenomena involved and of the great importance that an ultimate solution should be found it has continued to be since the war one of the most difficult and protracted problems in aeronautics. Owing to the body of experimental data which has been gradually built up, model and full scale, designers now know what peculiar properties in an aeroplane are liable to prove dangerous as far as recovery is concerned. There is unfortunately no mathematical precision about this process and the fact that machines can still be built which, unless they are tested in the spinning tunnel and the necessary modifications made, might become uncontrollable in a spin should be sufficient to indicate that a final solution is far front having been achieved. It seems exceedingly unlikely that there will ever be sufficient experimental evidence to enable a designer to predict confidently that his machine, if it be perfectly orthodox, will not have some vicious spinning tendency. On the other hand, any designer could build a perfectly safe aeroplane from the point of view of spinning if due regard had not to be paid to other items of performance and safety. The necessity for compromise in design becomes a major problem when spinning is one of the factors that have to be taken into account. There is ample evidence that this problem is being resolutely tackled by designers. All the same, the present position cannot be regarded as satisfactory and, unless some new device is produced which will remove autorotation from the possible regimes of an aeroplane, we must continue to progress along already well‐tried lines.

A study of the effect of curvature on fully developed turbulent flow

1—The solution of many important problems in aeronautics and hydraulics depends largely on the behaviour of turbulent flow along curved surfaces. In flow along plane surfaces the following method has proved to be successful. The laws of turbulent velocity distribution were investigated in straight tubes and channels of constant cross-section and the results applied to the boundary layer with variable thickness. The present work has undertaken with the idea of isolating the effect of curvature on the turbulent flow as much as possible, by using a curved channel of constant curvature and cross-section. It is hoped that the results of these experiments may be applied later to the general case of curved boundary layers.

New Methods of Research

IT is twenty years ago almost to the clay since the world was saddened by the news of the death of one of its heroes—Wilbur Wright. The inspiring story of the successful attack made by the two brothers, Wilbur and Orville, on the age‐long problem of human flight is too well known to be told at length here. But it is remarkable that the first flight by a motor‐driven aircraft on December 17th, 1903, was made only two years after Chanute, in a speech before the Western Society of Engineers, had felt compelled to use such cautious words as these: “There is some hope that, for some limited purposes at least, man will eventually be able to fly through the air.” Chanute made that speech when introducing a lecturer none other than Wilbur Wright himself. One wonders what the lecturer thought. What he said is on record and I quote a passage which tells us what it was that turned his and his brother's attention to the problem of flight: “My own active interest in aeronautical problems dates back to the death of Lilienthal in 1896. The brief notice of his death which appeared in the telegraphic news at that time aroused a passive interest which had existed from my childhood, and led me to take down from the shelves of our home library a book on ‘Animal Mechanism,’ by Professor Marey, which I had already read several times. From this I was led to read more modern works, and, as my brother soon became equally interested with myself, we soon passed from the reading to the thinking, and finally to the working stage.”

Aircraft and Naval Technique

PHYSICISTS are well acquainted with the relationship which exists between naval and the aeronautical problems. Although the specific gravity of water is a thousand times greater than that of air, the similitude in their flow goes beyond the limits of mathematical analysis; but experiments in water, which have the advantage of being easy of application, although requiring certain precautions, have yielded a number of conclusions that have proved useful in the case of sections and other component parts of aeroplanes.

Aeronautical Research in Sweden

This paper contains a report on the principal aeronautical research work carried out by the Aeronautical Committee of the Royal Swedish Institute for Scientific Industrial Research. The Royal Swedish Institute for Scientific Industrial Research in 1925 appointed an Aeronautical Committee with the object of promoting–scientific technical research work and general development work in the field of aeronautics. In the first place work has been concentrated on such problems in aeronautics which are of particular importance with regard to special Swedish conditions. The Aeronautical Committee has been concerned in establishing an aeronautical chair, combined with an aeronautical laboratory, at the Royal Technical University in Stockholm. The aeronautical professorship is now established by Parliament, and a professor will shortly be appointed. The establishment of the aeronautical laboratory has been postponed for the present, but there is hardly any doubt that the laboratory will be in being within the next few years.

Unsolved Aeronautical Problems

IT is obvious that this subject is so vast and and that its nature is such, that it can only be dealt with haphazardly For that very reason it furnishes, perhaps, suitable subject matter for discussionI propose to choose at random a limited number of unsolved aeronautical problems, to state them, one by one, with the briefest possible comments so that there may be plenty of time left for what we hope will prove an illuminating and thought-inspiring discussionHere are the problems —(1)The propulsion of aeroplanes with constant power at varying altitudes(2)Jet propulsion of aeroplanes(3)Variable wing surface aeroplanes(4)Vertically ascending and descending flying machines(5)Fog landings(6)Sea-worthy flying boats(7)The ideal aerodynamic structure, small and large(8)The multi-engine room with ideal propeller distribution and without engine drag

SOME OUTSTANDING PROBLEMS IN AERONAUTICS.*

Journal of the American Society for Naval EngineersVolume 30, Issue 3 p. 627-643 SOME OUTSTANDING PROBLEMS IN AERONAUTICS.* , Search for more papers by this author , Search for more papers by this author First published: August 1918 https://doi.org/10.1111/j.1559-3584.1918.tb04826.x * Paper. slightly abridged, read before the Aeronautical Society of Great Britain at the sixth “Wilbur Wright” lecture in the Central Hall. Westminster. on Tuesday, June 25. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume30, Issue3August 1918Pages 627-643 RelatedInformation

Some Outstanding Problems in Aeronautics

Ten years ago the aeroplane was a curiosity—a means wherewith, by a tour de force, a man might lift himself from the ground and make a hazardous flight through quiet air—a means to attract curious crowds to fenced-in county fair grounds to witness the marvel of a body heavier than air actually rising from the ground and moving under some measure of control through the air, and returning safely to its starting point.What the aeroplane has become in this short but poignant decade of the world's history, and what it stands for to-day, this audience knows too well to need specification in detail.It is perhaps well within the limits of conservatism to say that no achievement of man's inventive and constructive genius has undergone more intensive, more rapid, or more potentially significant development than has that of flying with an apparatus heavier than the air in which it moves.

Stability in Flight

ALTHOUGH I am quite incompetent to hold any opinion on problems in human aeronautics, I venture to submit that the inference drawn by Prof. D'Arcy Thompson from the flight of certain birds (p. 409) does not agree with accurate observation, and may prove misleading.

Scientific Research in Aeronautical Problems

The bearing of pure scientific research on practical scientific developments has been demonstrated again and again ; and interesting and valuable as are all aeronautical attempts, it is more than probable that the solution of flight and aerial navigation may be achieved after all by the physicist or the meteorologist. Just now, this thought is borne in on us by the physical experiments to determine the resistance of the air of M. L'Abbé Le Dantic and M. Canovetti, and by the publication of the annual bulletin of the Meteorological Commission of the Bouches du Rhône. There are some observations in this of the direction, frequency, and force of the wind made at the Marseilles Observatory at the height of 75 m. Such observations are preliminary steps to a meteorological knowledge of the conditions of the lower and upper atmospheres essential to the making of any seasonal maps of the winds; without such maps many practical aeronauts who look to utilising the wind forces for the purposes of motion consider aerial navigation doomed to remain empirical.