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of force centres of a scries of cambered round bodies derived from a torpedo-like body of revolution. The effects of placing fins on the rear of the body of revolution arc also included. Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical No. 1228. Behaviour of the Laminar Boundary Layer for Periodically Oscillating Pressure Variation. Research Council, Reports and Technical Memoranda of the United States National Advisory Com ('Verhalten der laminaren Grenzschicht bei periodisch mittee for Aeronautics and publications of other similar Research Bodies as issued schwankendem Bruckverlauf.' Ludwig Prandtl zum 70. Geburtstage, Schriften dcr Deutschen Akademie der Luftfahrtforschung, pp. 247-255. (To Ludwig Prantl FRANCE Furthermore, a few requirements about the dimen upon his 70th birthday, Publications of the German sions of the motors and the number of poles (with Academy for Aviation Research), Berlin 1945.) By PUBLICATIONS SCIENTIFIQUES ET TECH regards to an economical use of the alternator) are August Wilhelm Quick and K. Schroder. NIQUES DU MINISTERE DE L'AIR given. Magasin C.T.O., 2 Rue de la Porte d'Issy, Paris XV An extract is presented of theoretical results from a RAPPORTS Report F. 54. Theory of the oscillating Wing with more detailed report on the growth of the laminar Acrodynamically Balanced Control Surface in a Two- boundary layer on an undulated surface. For a surface No. 228. La Recherche du Nuage Radioactif. dimensional, Subsonic, Compressible Flow. By Dr R. which was undulated about the mean of a flat plate, (Research into Radioactive Cloud.) By H . Garrigue. Timman and Ir. A. I. van de Vooren. (In English.) the drag was shown to be appreciably less than that The author investigated the existence of radioactive for a flat plate at very low Reynolds numbers; how In this report a direct formal solution in terms of cloud in France, following the atomic bomb explo ever, the onset of transition on the undulated plate known functions is given for the aerodynamic forces sions. The tests were conducted in flight at 6,000 occurred at Lower Reynolds numbers than on the acting on an oscillating wing with acrodynamically metres in July 1946 and at 8,000 metres in July 1948. flat plate. balanced control surface in a two-dimensional, sub A radioactive body having an apparent period of sonic, compressible flow. This solution is based on the No. 1253. Flow Measurement by Means of Light 25±5 hours was detected in both cases. linearized equations of motion. All results arc given in Interference. ('Stromungsmessung durch Lichtinter- a form accessible to numerical computation. No. 229. Anisotropic, Symétrié, Hétérogénéit en ferenz.' Zentrale für wissenschaftliches Berichtswesen Elasticity. (Anistropy, Symmetry and Heterogeneity in über Luftfahrtforschung (ZWB) Berlin-Adlershof, Elasticity.) By A. Brodeau. Forschungsbericht Nr. 1167, February 1, 1940.) By AUSTRALIA Th. Zobel. COUNCIL FOR SCIENTIFIC AND INDUSTRIAL After notes on fundamental notions and the nota There has been under development for the high RESEARCH tion adopted, the author discusses clastic phenomena speed wind tunnel of the LFA an optical measuring 314 Albert Street, East Melbourne C2, Victoria in the vicinity of a boundary separating two homo arrangement for the qualitative and quantitative geneous isotropic bodies of different mechanical AERONAUTICAL RESEARCH REPORTS investigation of flow. By the use of interference properties, non-homogeneous isotropic bodies, fibro- ACA-41. The Motion and Deformation of Aircraft in measurements, the determination of density at the stratified bodies separated by a boundary parallel to a Uniform and Non-Uniform Atmospheric Disturbances. surface of the bodies being tested in the air stream and common plane of symmetry, the other planes of By J. R. M. Radok, B.A., and Lurline F. Stiles. in the vicinity of these bodies can be undertaken. symmetry being also common, non-homogencous July 1948. The results obtained so far in the simple preliminary fibro-stratified bodies, fibro-stratified bodies in con investigations show that it is possible, even at a low tact with an anistropic body, fibro-stratified bodies A theory is developed for flexural and torsional Reynolds number, to obtain the density field in the placed symmetrically about a boundary and fibro- deformations of an aircraft travelling in disturbed neighbourhood of a test body by optical means. stratified bodies with variable symmetry in space. The atmospheric conditions. The two cases treated Simple analytical expressions give the relation between report concludes with a study of crystals. correspond to a symmetrical uniform gust and to an density, pressure, velocity and temperature. asymmetrical gust, the Wagner-effect being neglected No. 230. Les Mcsures de Température dans la In addition to this, the interference measurement in each case. Technique des Moteurs d'Aviation. (Temperature furnishes valuable data on the state of the boundary The integro-differential equations obtained for the Measurement in the Study of Aero-Engines.) By P. layer, that is, the sort of boundary layer (whether curvature, and the angle of twist of the wing, for the Vernotte. laminar or turbulent), as well as the temperature and vertical acceleration, the angle of pitch and the angle velocity distribution. The author draws on twenty years' experience of of roll (in the asymmetrical case) at the centre of mass temperature measurement in aero-engines to assist of the aircraft are new. In contrast with former others to achieve accurate results. He discusses the investigations, acceleration records taken in flight are GREAT BRITAIN proper operation of thermocouples, the effective used to specify the atmospheric conditions. In this AERONAUTICAL RESEARCH COUNCIL temperature of thermocouple weld, the measurement way it has become feasible to determine actual gust H.M. Stationery Office, London of the e.m.f. produced by the couple, the calibration velocities based on reliable physical data and to of thermocouples and the disturbances in tempera demonstrate the small effect of wing flexibility on the R. & M. No. 2242. A Theoretical Discussion of ture produced by the presence of the thermocouple. acceleration at the centre of gravity of the aircraft, High-lift Aerofoils with Leading-edge Porous Suction. Consideration is also given to the use of mercury subject of course to the assumptions made in the By B. Thwaites. July 1946. (2s.) thermometers and variable resistance thermometers. present theory. It is shown in this report that by the principle of Finally he discusses the accuracy with which tempera An approximating method is developed for the porous suction high lift coefficients can be obtained on tures to be measured arc defined. solution of the governing equations which enables the thin aerofoils by the use of surprisingly small amounts investigation of any accelerometer record once a of suction. It is more economical to use porous fundamental set of computations has been performed. suction than to suck through a slot at or near the NETHERLANDS The application of the theory to a typical four- leading edge, and it is necessary to realize that in engined aircraft is given in detail and one fairly NATIONAL LUCHTVAARTLABORATORIUM general the principles involved in the two types of complicated and several simple acceleration records Sloterweg 145, Amsterdam suction arc rather different. The discussion is restricted arc analysed. The solutions agree well with experi Report A. 950. Drag and Pressure Measurements to aerofoils with rounded leading edges, since it is mental results and arc presented in the form of time with Plaster Spheres in Wind tunnels 3 and 4 of the difficult to predict theoretically the effect of any type records. National Aeronautical Research Institute. By Ir. S. I. of suction on flow near a sharp edge. A short review of previous work is given as well as Wiselius. (In English.) There are given graphs showing estimates of the suggestions for the further development of the present quantities of air to be sucked on three different Drag and pressure measurements with two plaster theory. typical thin sections to produce any reasonable spheres in the closed working section of wind tunnel 3 desired lift coefficient. It seems that to obtain a lift and the open working section of wind tunnel 4, carried coefficient of 2 0 on a 7 per cent. thick section on a U.S.A. out to determine the turbulence of airflow, are dis fighter aircraft when landing, a quantity of air of 0·5 cussed in this report. A description of the plaster spheres NATIONAL ADVISORY COMMITTEE FOR cu. ft./sec. per foot span is sufficient, to be sucked and of the attention paid to the suspension of the AERONAUTICS over the first 2 per cen. of the chord. Half this spheres in the wind tunnels is given. It is concluded that TECHNICAL MEMORANDA (TRANSLATIONS) quantity of air sucked would suffice for a lift coefficient the turbulence of airflow in wind tunnel 3 is rather low. of 1·5. The design of the leading-edge shape is import Secretary, N.A.C.A., Washington, D.C. ant but suitable aerofoils have already been designed Report A. 1011. Some Remarks about High- No. 1110. On Combustion in a Turbulent Flow. in Ref. 1. Frequency Rotary-Current Electric Motors for Driving (Jour . Tech. Phys.' (U.S.S.R.), Vol. XIII, Nos. 9-10, Model Propellers. By Ir. J . G. Slotbaom. (In English.) 1943, pp. 520-530.) By. K. I. Shelkin. R. & M . No. 2304. Preliminary Measurements of The characteristics introduced by the turbulence in The requirements to be met by electric motors for the Boundary Layer in the 11-in. Supersonic Wind the process of the flame propagation arc considered. driving model propellers can be expressed in a simple Tunnel. By W. F. Cope and G. G. Watson. August On the basis of geometrical and dimensional con condition. Starting from the formula giving the power 1946. (is. 6cl.) siderations an expression is obtained for the velocity required as a function of the propeller diameter, the The velocity and Mach number distributions in the of the flame propagation in a flow of large scale of number of revolutions and the torque coefficient, a boundary layer of the National Physical Laboratory relation is derived which represents the power for all turbulence. 11-in. Supersonic Wind Tunnel have been measured motors as a function of the revolutions per min. only. No. 1227. Moments of Cambered Round Bodies. at Mach numbers of 1·5 and 2·4. The Reynolds This is evident after having been shown that the ('Momente von gekrümmten Rundkörpern.' Ludwig number, based on the distance from the throat as possibility of carrying out useful measurements at a Prandtl zum 70. Geburtstag, Schrifte de Deutschen representative length, was varied from 2¼ million to 7¼ reasonable wind speed—especially measurements con Akademie de Luftfahrtforschung, pp. 139-151. (To million. The results show that the boundary layer is cerning the stability at minimum speed—requires a Ludwig Prandtl upon his 70th birthday, Publications of supersonic to within a very short distance of the wall the German Academy for Aviation Research), Berlin and that the representation of the distribution by value of of about 100 m/sec. It is not necessary to 1945.) By Günther Kempf. either a logarithm or a power law becomes less accurate as the Mach number increases. choose higher values. Results arc presented for the moments and position 390 Aircraft Engineering
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Dec 1, 1949
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