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U.S.A. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS TECHNICAL MEMORANDA (TRANSLATIONS) Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical No. 1200. Measurement of Oil-Film Pressures in Journal Bearings under Constant and Variable Loads. Research Council, Reports and Technical Memoranda of the United States National Advisory Com ('Messung des Olfilmdruckes in ruhend- und wechselnd mittee for Aeronautics and publications of other similar Research Bodies as issued helastetren Gleitlagern.' Jahrbuch 1937 der deutschen Luftfahrtforschung, pp. II 67-II 78.) By A. Buske and CANADA (Algemene beschouwingen inzakc do langsstabiliteit W. Rolli. en- besturing van staartloze vliegtuigen, serie I.) (In NATIONAL RESEARCH COUNCIL In a study of journal bearings, the measurement of Dutch.) By A. J . Marx and J . Buhrman. Ottawa the oil-film strength produces some significant This report consists of a series of six reports drawn information. A new instrument is described by means DIVISION OF MECHANICAL ENGINEERING up during the war and dealing with several problems of which the pressure of the oil film in bearings (under ENGINE LABORATORY of the longitudinal stability of the all-wing type aero constant or alternating load) can be measured and plane: In report V.1307 the longitudinal static stability Report No. ME-173, December 31, 1948. Notes on recorded. With this device, the pressure distribution of the tailless aeroplane as affected by sweepback, Some Charge Heating Anti-Icing Tests with an Axial in the lubricating film of a bearing bushing was aspect ratio, taper ratio and wash out of the wing is Flow Turbo-Jet. By J. J. Samolewiez and G. A. measured (under different operating conditions on a considered. An estimation of centre of gravity position Macaulay. journal bearing) in the pulsator-bearing-testing ma for swept back wings is given from a structural point Some charge heating experiments with a Jumo 004 chine. These tests arc described and discussed. of view. The longitudinal control by means of are described. The tests were made under simulated 'elevons' is dealt with in report V.1313. Calculated No. 1236. A Class of de Laval Nozzles. ('Institut icing conditions on the test bed using an auxiliary trim curves arc given for several forms of wing shapes. Mekhaniki Akademii Nauk Siuza, SSR.' Prik- combustion heater fed by air bled from the last stage Report V.1320 gives an estimation of the flight path ladnaia Matematika i Mekhanika, Tom XI, 1947.) of the compressor to supply heat. The method used angle and the fore and aft attitude as a function of By S. V. Falkovich. to estimate the theoretical heat requirements and the speed. The results of the above-mentioned calcula actual heat used is described. A description of the A study is made herein of the irrotational adia- tions arc compared with the characteristics of a real batic motion of a gas in the transition from subsonic icing runs with and without heat is given, and some tailless aeroplane (DFS 193) as determined in the to supersonic velocities. A shape of the dc Laval points relative to charge heating anti-ice experiments wind tunnel (Report V.1321). nozzle is given which transforms a homogeneous are touched upon. The reports V.1327 and V.1329 are written as a plane-parallel flow at large subsonic velocity into a During the experiments, the compressor digested preparation to the dynamic longitudinal stability of supersonic flow without any shock waves beyond the small portions of ice which resulted in nicking of the the tailless aeroplane. The former gives an estimation transition line from the subsonic to the supersonic compressor blades. of the moment of inertia about the lateral axis, regions of flow. The method of solution is based on LOW TEMPERATURE LABORATORY which appears to be low in comparison with con integration near the transition line of the gas equations ventional aircraft. The second report deals with the of motion. Report No. MD-32, August 17, 1949. Analysis of damping in pitch, for which a rather rough estima Experiments on Inducing Precipitation. By J . L. Orr, No. 1239. Two-Dimensional Motion of a Gas at tion is given. D. Fraser and K. G. Pettit. Large supersonic Velocities. ('Institut Mekhaniki The text of this report is that of the lecture entitled Akademii Nauk Souiza, SSR.' Prikladnaia Matema Rapport V.I400. General Consideration of Longi 'Canadian Experiments on Induced Precipitation' de tika i Mekhanika, Tom XI, 1947.) By S . V. Falkovich. tudinal Stability and Control of Tailless Aeroplanes. livered to Section Meeting, Water l(C)/2, on Appraisal (Algemene beschouwingen inzake de langsstabiliteit The equation of motion of a gas is investigated for of Water Resources, at the United Nations Scientific en- besturing van staartloze vliegtuigen, serie II.) large supersonic velocities and a method is shown for Conference on the Conservation and Utilization of the approximate integration, which gives sufficient (In Dutch.) By A. J . Marx and J . Buhrman. Resources, held at Lake Success, N.Y., on August 17, accuracy for Mach numbers greater than 4. This collection of reports describes the dynamic behaviour of the tailless aeroplane: In V.1333 a A co-operative investigation into induced precipita No. 1245. Lift Force of an Arrow-Shaped Wing. method is developed to calculate the elevon deflexions tion has been undertaken in Canada and a total of ('O Pod'emnoi Sile Strelovidnogo Kryla v Sverk- during flight just before landing and the most forward 59 trials have been made using dry ice as an inoculant. hzvukovom Potoke.' Prikladnaya Matematika i centre of gravity position, which is admissible from In addition, the results of 20 similar trials performed Mekhanika, Vol. X, 1946, pp. 513-520.) By M. I. this point of view. Numerical application of the in Australia arc compared. Gurevich. theory is given in V.1336 for full span elevons. The analyses of these experiments, of which about The lift at supersonic speeds of a thin delta wing Finally the dynamic longitudinal stability is con half were selective and half were random, show that (a) extending outside the tip Mach cone and (6) con sidered in V.1343. The basic behaviour of the tailless precipitation reached the ground on 24 per cent of all tained within the tip Mach cone is obtained. By use aeroplane appears to be the same as for conventional Canadian trials whereas in selective tests with only of Busemann's conical flow transformations, the aircraft. No particular difficulties are to be expected supercooled cumulus clouds precipitation reached problem is reduced to the solution of the Laplace when static longitudinal stability is provided for. the ground on 43 per cent of the trials. equation within the Mach cone. Conformal-mapping Damping and frequency of the oscillations arc cal The meteorological conditions favourable to in methods are used. culated in a few cases. ducing precipitation and for ensuring that such pre cipitation reaches the ground arc stated. GREAT BRITAIN Rapport V.1401. General Consideration of the Reference is made to the generation of clouds of Lateral Stability and Control of Tailless Aeroplanes. AERONAUTICAL RESEARCH COUNCIL ice crystals in clear air by inoculation. (Algemene beschouwingen inzake de dwarsstabiliteit H .M. Stationery Office, London It is concluded that precipitation can be artificially en- besturing van staartloze vliegtuigen, serie III.) induced under the appropriate meteorological con R. & M . No.' 2252. Profile Drag Measurements at 1944 (In Dutch). ditions. The limitations of the method arc discussed Compressibility Speeds on Aerofoils with and without An estimation is given of the lateral stability and it is emphasized that induced precipitation can Spanwisc Wires or Grooves. By H. H. Pearccy. derivatives of the tailless aeroplane as a function of only supplement natural rainfall. Comments arc made August 1943. (4s.) the sweep-back angle, the dihedral and the wash out. on the application of the method to agriculture, To this end use was made of the results of wind tunnel Profile drag measurements in the National Physical forestry and water-power. measurements and of theoretical approximations Laboratory 20 in. x 8 in. High Speed Wind Tunnel on The economic significance of induced precipita (rotary derivatives). aerofoils of 5-in. chord demonstrated that, for this tion is considered to be specific to a given application Three forms of lateral control are discussed. In the small chord (R=l·0xl06 to l·8xl06), wires are and to a particular region and therefore its usefulness first place it is investigated how far lateral control rather unsuitable for fixing transition at high speeds on can only be assessed on the basis of individual re with the clevons (deflecting in opposite directions) account of compressibility effects that occur at quirements. only is possible. The second possibility considered is comparatively low Mach numbers (about 0·5). From the scientific standpoint the results that can related to control with elevons which arc coupled to Visual observations confirmed that these effects were be obtained are noteworthy and it is considered that the rudder and finally the conventional form of control due to the formation of shock waves at the wires. the subject merits further study. with ailerons is discussed. Further tests on a 1·ft. chord model of EC 1250 showed that, with this larger chord, compressibility NETHERLANDS effects at the wires arc of less importance and hence FRANCE NATIONAAL LUCHTVAARTLABORATORIUM that wires are more suitable for fixing transition. The PUBLICATIONS SCIENTIFIQUES ET TECHNI C (aerofoil chord basis) of the wires themselves is also Sloterwcg 145, Amsterdam QUES DU MINISTERE DE L'AIR much smaller. The bare aerofoil gave low drag values Rapport V.1314. Literature Study of the Lateral (corresponding to theoretical values for transition Magasin C.T.O., 2 Rue de la Porte d'lssy, Paris (XVe) Stability and Control of Tailless Aeroplanes. (Litera- between 0·5c and 0·6c) for Reynold's numbers up to tuurgegevens over de dwarsstabiliteit en- besturing van RAPPORTS 4x10 6. At 0 deg. incidence the variation with speed, staartloze vliegtuigen.) 1943 (In Dutch). By S. Wynia. No. 231. Contribution a l' Etude des Pertes de both for the aerofoil with and without wires, was A historical survey of the construction and charac Charge Singulieres. (Contribution to the Study of consistent with the calculated incompressible flow teristics of a number of tailless aeroplanes is given. Singular Pressure Losses.) By C. H. Cottignics. variation for a given position of transition over a Special attention is paid to the static directional (420 francs.) Mach number range of 0·15 to 0·68 (R= 1x106 to stability. 4 x 106), and over a slightly smaller range at 1 deg., The research by the author relates principally to It is concluded that, however small this is, satis a 7 deg. conical diffuscr. He shows the influence of thus confirming theoretical indications that there is factory stability can be obtained by means of sweep- the Reynolds number and the velocity distribution at practically no compressibility increase in the profile back and end-plates or fins. The influence of several the entry on the pressure loss coefficient of the drag of aerofoils at Mach numbers below the critical. design parameters on the characteristics of the aero diffuscr. To vary the entry velocity distribution of the Measurements in the 1 ft. diameter High Speed plane arc discussed briefly. diffuscr, he uses upstream 'elbows' of which he has Tunnel on a 2-in. chord model of N.A.C.A. 2417 Rapport V.1399. General Consideration of Longi studied and measured the pressure losses. A short section showed that grooves were ineffective in fixing tudinal Stability and Control of Tailless Aeroplanes. final chapter relates to a 15 deg. diffuscr. transition. March 1950 89
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Mar 1, 1950
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