FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1914
1914 - 0774.PDF
It was suggested by one speaker at a meeting of the Aeronautical Society, during the session which has just closed, that the field of research in aeronautics was so vast that the establishment of laboratories in connection with the works of aeroplane manufacturers was highly desirable, and would in no way militate against or limit the activities of the National Physical Laboratory at Teddington. If any proof were needed in support of this statement it is adequately afforded by the most recent publication of M. Eiffel—Nouvelks Recherches sur la Resistance de rAir et VAviation—a work that deals with the experiments he has conducted since r9ir in his new laboratory at Auteuil. This book is now in two volumes, one of which gives the text, and the other the tabulated numerical data and diagrams relating to his researches. Coming so soon after the issue of the Technical Report of the Advisory Committee, one is tempted to make comparisons between them, but they do not lend themselves to this process because of the differences in the subjects touched upon, and the variations in the nature of the objects of the experiments recorded. The staff of the N.P.L., while developing research into the various factors affecting the aerodynamic properties of a limited number of aeroplane wings and propellers have, in the main, been concerned with new ground, new lines and methods of research, always the more difficult work, notably in regard to stability, to which one-third of the recent Blue Book is entirely given up. The R.A.F. also contributed a report on full scale work. M. Eiffel, on the other hand, has been mainly concerned with the aerodynamic properties of a large number of aerofoils, and the study of scale models of complete aero planes, seaplanes and airships. Hence the subject- matter of the experiments at the two laboratories are dissimilar, although research of a like character to some of Eiffel's, but on a less pretentious scale, has already been conducted at the N.P.L. Some of the work recorded by Eiffel concerns old and superseded machines, as is only to be expected, and it is because the publication of the results of research of a number of experimenters in volume form necessarily means delay, that we have so repeatedly advocated the more frequent issue of reports. As M. Eiffel observes, however, much of the results of his work has been already communicated to interested persons, so that progress has not stagnated through the lack of sufficient data. After a description of the plant and the methods of testing at the laboratory at Auteuil, M. Eiffel gives a series of diagrams relating to the. resultant of the forces acting upon an aeroplane under varying conditions during flight, as well as the inter-relation between the weight supported, speed, and power, with typical applica tions that should prove of value to the designer. He also examines the effect of altitude upon performance of an aeroplane and upon the power of the engine. The results of tests for determining the air resistance of spheres, convex and concave surfaces, cylindrical bodies ® <& ROYAL FLYING CORPS. THE following promotion was announced by the Admiralty on the J 6th inst. :— Commander F. R. Scarlett, granted acting rank of Captain, to date July 14th. The following appeared in the London Gazette of the 17th inst. :— R.F.C—Military Wing.—The appointment of Lieut. Leslie Da C. Penn-Gaskell, 3rd Batt. Norfolk Regiment, as a Flying Officer, is ante-dated to Feb. 26th, 1914, but without pay or allow ances prior to March 18th, 1914. Military Aeroplane Competition in U.S. A. A COMPETITION open only to American makers is to be held JULY 24, 1914. which vary in the ratio of length to diameter and in the formation of the ends, struts and models of aeroplane bodies at speeds varying between 4 and 30 metres per second are then recorded, and he proceeds to deal with his experiments on wings, which are of an extremely interesting nature. In this chapter over thirty wing sections are treated, many of which are similar to current types, although some are of curious design, and we note amongst them those of the Wight seaplane and the Bristol scout. As regards the former, while the curves of lift and drag, the ratio of lift to drag and the pressure distribution are given, the movement of the centre of pressure with varying angles of incidence are not recorded, although it can be deduced from the data supplied. In the results of a wing, how ever, of similar design, but inferior aerodynamically, it is shown that the centre of pressure varies from about 0-34 to 0*42 of the chord from the leading edge for all angles of incidence, which accounts largely for the excellent flying qualities of the machine to which it is fitted. The high efficiency of the Coanda wing section on the Bristol scout, concerning which M. Eiffel speaks in terms of high praise, is also indicated, the ratio of lift to drag at from o" to about 40 angle of incidence being approximately o-o6. The next chapter deals with the interference of various wing surfaces when placed in tandem or when staggered. As regards the latter, some confirmation of the N.P.L. results is given, since a general increase in efficiency is shown when the upper plane is placed in advance of the lower to the extent of o-4 to 0^45 of the chord ; although, as Eiffel states, for some flight angles there is little difference between the results obtained, and those for the commoner arrangement—non-staggered. It is interesting to note that the lift curve is very slightly improved for the upper surface by staggering the planes, while that for the lower surface is much diminished, but as, however, the drag is also reduced by a greater or a proportionate amount at ordinary flying angles, the ratio of lift to drag of the two wings is either increased or but little affected. The experiments on model aeroplanes are then fully considered. A novel type of machine with tandem planes, and a cigar-shaped body with the propeller in the middle of its length, being amongst those treated in the text. The next chapter gives much data respecting the air resistance of floats and of bodies. Chapter VIII is devoted to the consideration of airships of various makes, including the Clement Lebaudy, Fleurus, and the Astra-Torres. The last two chapters deal with wind pressure on airship sheds and the propeller—the latter being exceptionally well treated, especially as regards the effect of the number of blades on power and efficiency. The work—a truly monumental one, well up to the standard of its predecessors — concludes with seven appendices, two of which relate to the method employed by Drzeweicki in the design of propellers. <$) ® by the U.S. military authorities at San Diego, Cal., next autumn. There will be prizes of $12,000, $10,000 and $8,000 for the three machines which make the best performances, while orders will be given for at least twenty other machines. Competing aeroplanes will be required to carry a pilot and passenger, have a speed varia tion ranging from 40 to 70 m.p.h., and be capable of rising 4,000 ft. in 10 nuns., while other points which will be taken into con sideration will be handling of machine in restricted space, quickness of assembling and dismantling, ability to land on and start from rough ground. The total amount which will be available for this competition and the other aeronautical requirements of the U S Army is $250,000.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
