FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1928
1928 - 0065.PDF
JANUARY 26, 1928 11 THE AIRCRAFT ENGINEER SUPPLEMENT TO FLIGHT Fig. 14. Internal expanding Shoe Brake, proportions. (See previous pages.) Angular A Correction. In Mr. Dowty's article in the December issue, two mis- prints occurred in the column headings of the table on page 79. Thus the heading of col. 7 of the table should have read RA + p, and that of col. 8 should have read • 0334 V- = Tj. Will readers please make the necessary RA + ftcorrections in their copies. TECHNICAL LITERATURE. SUMMARIES OF AERONAUTICAL RESEARCH COMMITTEE REPORTS. FULL-SCALE MEASUREMENTS OF LIFT AND DRAG OF THE FOKKER F.VII—3M MONOPLANE. By J. J. K. HARDY, B.A. Presented by the Director of Scientific Research. R. & M. No. 1096. (Ae. 275) (4 pages and 5 diagrams.) April, 1927. Price 6d. net. Considerable interest has been taken in the performance of the Fokker aeroplane, especially as affecting control, and it has been claimed that this aeroplane has exceptional control properties. The lift curve of the Fokker type F.VII aeroplane has been measured in order to determine the incidence at the stall, as a preliminary to control experiments of the aeroplane at, and near, this incidence. The lift and drag have been measured from 3|° to 15° incidence, corresponding to speeds from 55 to 70 m.p.h. Two sets of curves have been obtained, one with the engines throttled right back, and the other with the engines switched off. The corresponding maximum lift coefficients are 0-78 and 0-73. Quantitative observations of the efficiency .of the controls when stalled will be made in accordance with a scheme drawn up by the Stability and Control Panel. A preliminary report on the lateral control of the Fokker F.VII has already been issued (T. 2403).* • T. 2403 (unpublished). Preliminary report on lateral control of FokkerF.VII—3M with three Lynx engines.—H. L. Stevens. R.A.E. Report B.A. 644. THE DISTRIBUTION OF PRESSURE OVER A MONOPLANE AND A BIPLANE WITH WINGS OF UNEQUAL CHORD AND EQUAL SPAN. By A. S. BATSON, M.A.. A. S. HALLIDAY, B.SC, D.I.C., and A. L. MAIDENS. R. & M. No. 1098 (Ae. 277). (28 pages and 14 diagrams.) February, 1927. Price Is. 3d. net. A number of aeroplanes have been built with unequal upper and lower wings, and a first set of experiments was undertaken to find the distribution of pressure over a biplane with wings of unequal chord and span so as to determine the loads carried by the separate wings for stress calculation purposes (see R. & M. 997).* The present experiments extend kpowledge to the case when the wings have an unequal chord by an equal span. Measurement of pressure distribution over a R.A.F. 15 biplane with chord of lower plane two-thirds that of upper and with equal spans ; gap three-quarters of chord of upper plane ; stagger 20°. Measurements also made on a R.A.F. 15 mono- plane. Range of incidence from — 4C to -r 40° by 4° steps. The usual preponderance of loading towards the wing-tips is not quite so marked for either the present biplane or monoplane as for the biplane with unequal chord and span (see Figs. 4-6, 8 and 9 of report). As there are no data for a normal R.A.F. 15 biplane with square wing-tips, measurements might be extended to this type by using the larger plane of the present biplane with a wooden one as a dummy. * R. and M. 997. " The distribution of pressure over a biplane with wings of unequal chord and span."—Irving and Batson, December, 1925. WIND TUNNEL EXPERIMENTS ON THE EFFECT ON THE MAXIMUM LIFT OF WITHDRAWING AND DISCHARGING AIR FROM THE UPPER SURFACE OF AN AEROFOIL. By W. G. A. PERRING, R.N.C., A.M.I.N.A., and G. P. DOUGLAS, M.C., D.S.C. Presented by the Director of Scientific Research. R. & M. No. 1100 (Ae. 278). (5 pages and 8 diagrams.) April, 1927. Price 6d. net. Several attempts have been made to increase the maximum lift coefficient of an aerofoil, and the Handley-Page slot is an application of a principle whereby the stalling of the aerofoil is delayed to a much larger angle of incidence than in the ordi- nary wing section, and hence gives increased lift. The stall occurs when the streamlines past the aerofoil cease to follow the upper surface, and this happens when the energy in the air flowing near this surface is so reduced by the viscous forces that it can no longer force its way against the increasing positive pressure. Experiments have been made in Germany on the effect of the flow due to discharging or sucking away air at the point where the flow leaves the boundary, and some experiments are here described which were carried out at the R.A.E. on an aerofoil, the air being discharged or removed from its upper surface. An aerofoil was made up having slots running along ite span and provided with means by which lift could be measured while air was discharged or withdrawn through these slots. Preliminary tests were made to find the relative merits of discharging the air tangentially and of sucking it in and also the effect of varying the quantity of air through the slots. By discharging air tangentially along the upper surface of the aerofoil at a point 0-13c from the leading edge the maximum lift coefficient was increased by 0 • 35, and this value was increasing steadily as the quantity of air discharged was increased.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
