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Aviation History
1925
1925 - 0026.PDF
JANUARY 15, 1925 £74,000 in respect of the 80 h.p. Gnome and the le cylinder mounted in the leading edge of an aerofoil. The experiments cannot, of course, be regarded as conclusive proof of the suitability, granting the mechanical possibility of mounting and operating such rotors, of the rotating cylinder as a means of obtaining better efficiency from aerofoils. The experi- ments do show, however, that a very considerable increase in maximum lift coefficient is obtainable in this manner, but the question of drag still has to be settled. The percentage increase in maximum lift coefficient amounts, in the aerofoil tested, to no less than 73-3 per cent. Although not equal to the increase of lift obtainable with the Handley Page slotted wing, it is by no means to be despised, and it should be remembered that whereas the Handley Page wing has now undergone fairly extensive develop- come next, with an award of £40,000 in respect of the merit, the rotor wing has but recently been made the Sopwith "Cuckoo," "Dolphin," " Snipe," and " Sala- subject of study. There is as yet no possibility of mander " aeroplanes, and in view of the formidable telling how much lift can be obtained. The rotor series of machines of unquestioned usefulness pro- by itself has been shown by the American experiments duced by that famous firm during the War, few will described in FLIGHT last week to be capable of giving quarrel with the award. lift coefficients far in excess of anything obtained with In connection with the use by the United States of an aeroplane wing, but the L/D ratio is not very good, except at very low forward speeds. It may well be. Rhone engines (in addition to £200,000 already received from H.M. Government), £75,000 in respect of the Gnome Mpnosoupape engine, and the Aircraft Manufacturing Company £65,000 in respect of the use by the United States of De Havilland machines during the War and up to July 25, 1919, and the Aircraft Manufacturing Company and Capt. de Havilland £35,000 in respect of D.H. aeroplanes used by Great Britain. The next largest individual award, one of £50,000, goes to the Bristol Aeroplane Company in respect of the Bristol Fighter, of which large numbers were built and used during the War, and which was one of the most popular of all British aeroplanes. The Sopwith Aviation and Engineering Company America of British aeroplane and engine designs, etc., it may be recollected that it was agreed that if the American Government placed with American manu- facturers orders for the production of British aero- planes, engines and accessories, the British Govern- ment would itself bear any liability in respect of the rights of the British manufacturers during the War. In considering the question the Joint Commission, consisting of three members of the Royal Commission and three representatives nominated by the United States Government, decided to classify the subject under three heads : The period during the War, the period between the end of the War and the date on which manufacturing in America ceased, and the future. It is worthy of note that the report states that there was no case in which the Joint Commission failed to come to a unanimous decision. Brief details of the machines, etc., which came under consideration in this connection are given in Appendix II to the Report. We have already referred to the award to the Aircraft Manufacturing Company. Handley Page, Ltd., are awarded £9,000 in respect of War-time use of the 0/400 machines, and the Bristol Aeroplane Company £2,500 in respect of the war use of the Bristol Fighter. The only aircraft firm to be awarded anything under the head " future user" is A. V. Roe and Co., Ltd., who are awarded £1,000. Mrs. Mynnie Porte, widow of the late Commander J. C. Porte, is awarded £1,500 in respect of post-War use (i.e., from July 25, 1919, to date of award) of flying boats. Taking it all round, the awards seem distinctly on the low side, especially the latter, possibly out of consideration for the terrible financial position in which the War left the U.S., and the appendices contain the names of claimants whom one would certainly have expected to have received awards, but whose claims have not been allowed. Doubtless, however, the very fullest particulars have been given to, and carefully considered by, the Royal Commission. The Rotor m si Elsewhere in this issue of FLIGHT we describe briefly certain experiments carried out at the Rijks-Studiendienst that for faster machines, the ordinary aerofoil wing, fitted with one or more rotors, may offer a better solution. From the curves published this week, obtained in the Amsterdam laboratory, it will be seen that there is a striking resemblance in effect between the wing fitted with a rotor in its leading edge and the Handley Page slotted wing. Both increase the maxi- mum lift coefficient, and both increase the angle at which the maximum lift coefficient occurs. In one way, the Handley Page slotted wing may justly be claimed to score over the rotor wing, unless the latter be found capable of developing much greater lifts than the slotted wing, in that no mechanical trans- mission or gear is required to give the necessary circulation of air, this function being performed, in the Handley Page wing, by the slots themselves. The fact that the Dutch experiments have shown that fitting the rotor has the effect of increasing the lift and the angle of maximum lift, while the American tests show the lift to be proportional to rotor speed, obviously suggests the use of rotors for maintaining lateral control at large angles of incidence. Certain experiments in this country, by the Royal Aircraft Establishment at Faxnborough, and by private air- craft firms, have proved that it is possible to design an aeroplane which remains perfectly controllable at angles much greater than the stalling angle, but only by the use of wing flaps having an area of approxi- mately one-third of the total wing area*, and corres- pondingly large tail surfaces. It would seem that there is at any rate very good reason to believe that the rotor may offer a solution of this difficult problem. If it does nothing else, it will have amply justified itself, for probably 90 per cent, of accidents are due to loss of control at low speeds. That certain not inconsiderable mechanical difficulties will arise is to be expected, but they should not prove altogether insuperable. ~/ The whole subject is one of such fascinating possi- bilities that it is to be hoped our own authorities will lose no time in putting a series of experiments in hand at the N.P.L., or at Farnborough, in order that this country may not be left behind other nations in voor de Luchtvaart at Amsterdam, by probing the problems of the rotating cylinder in all Dr. Wolff, director of that institute, on a rotating its applications to aviation. \ ••'• ••••.• • "•-.;•-• ' :•...:. 26
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