98 AIRCRAFT ENGINEERIN G May, 1929 Tw o British Air Ministry Official Books of Interest to Designers of all Countries ECHNICAL Report of the Aeronautical One may be excused a feeling tha t much earlier generous co-operation of the N.A.C.A. in Research Committee 1927-28. 2 Vols. work on this topic has been on too high a plane their variable density tunnel to compare with T [H.M. Stationery Office. Price 25s.] to appeal to those to whom it would be of our own model and full scale. It is difficult I t is difficult to believe that there is any- interest. Stability is deal t with in two interest to avoid a feeling that the points on which ing reports, one (1093) by Mr. Glauert on anon - aeronautical engineer, or indeed anyone seri agreement is good have been allowed rather dimensional form of the conventional stability ously interested in aeronautics who can fail more prominence than those on which it is analysis, the other (1118) b y Mr. Gates in which t o feel that the Technical Report of the Aero less satisfactory, but with the general recom an extract of the essentials is given specifically nautical Research Committee for 1927-28 is mendations of the report (1149) it is probable for the use of designers. Mr. Gates has an tha t most people will agree. of more than usual interest. It goes without enviable gift of writing readably. Amongst saying tha t it is a record of notable individual I t is impossible to feel entirely satisfied work—of which indeed there are far too many other subjects in this class are Mr. Glauert's with the style and make up of the books. We examples for it to be possible in the space avail discussion (1099) of the mass of earlier experi may congratulate ourselves on being spared a mental work on the variation of engine power able to do more than mention a few of the most repetition of the one enormous volume charac with height, and a most interesting analysis, significant. Its special value lies in the wide teristic of the two preceding years, but the by Mr. Howard and Mr. Spencer (1125), of the range of subjects of vital concern to the imme handica p of the size of page adopted becomes "hidden " margin of strength of aeroplane diate development of aircraft that receive more obvious each year. A striking example structures. suggestive treatment. It is inevitable that a of the advantage of illustrations in the text great part of any such publication should be (the general practice of both Göttingen and Three reports (1088, 1089, 1101) on slot in the nature of history. We are none the th e N.A.C.A.) is given by the first two reports and aileron control mark the second stage in worse for an opportunity to look back over the in Volume I—which are, however virtually th e history of this device. Its later develop road we have recently travelled. men t has become a topic for Parliament and lifted from Transactions A of the Royal Society, th e popular press. in which they first appeared! The objections The basic problems of hydrodynamics; scale t o changing to a larger size of page arc doubt effect; compressibility effects on aerofoils On the more academic side, Mr. Fage and less strong, but the inconvenience of the present and airscrews; slots for lateral control above Mr. Johansen continue their work on fluid size cannot be borne indefinitely. th e stall; the autogyro; methods of perform flow (1097, 1104, 1139, 1143) accumulating ance testing; variation of engine power with still further stores of ammunition for the grand The Report represents a great deal of work height ; the effect of supercharging; the per attack . The work is of an exceedingly laborious for the Secretary and his departmen t and (apart formance of the ideal streamline aeroplane; type . In the nature of th e case i t can a t present from the matte r of type just mentioned, which, interference of airscrew and bodies; stresses in bring little in the way of tha t clear cut agree however, may no t be his responsibility) we may beams of corrugated sheet—all these are dealt ment (or, for that matter, disagreement) with congratulate him on it and for the speed with with, generally by that precise combination of a theoretical prediction which is the true which it has been put together and published. theory and practice which constitutes true research worker's complete reward. The authors engineering, and in all a definite advance can are to bo congratulated on their unfailing be detected. In places the gains are slight. enthusiasm. This is especially noticeable in those subjects HANDBOOK OF STRENGTH Sir Thomas Stanton's high speed wind tunnel where the underlying theory is still weak— (1130) (in which aerofoils have been tested at CALCULATIONS experiment unless guided by theory, advances speeds as high as 1,200 m.p.h. is one more Official Air Publication 970. [His Majesty's bu t slowly. The outstanding example is the instance of his remarkable flair for that par Stationery Office. Price: 3s. 6d.] high-tip-speed airscrew, of which the best that ticularly difficult work, on the borderline can be said is tha t (unlike beer) some are worse between physics and engineering, which com This is the third edition of the manual with tha n others, but none are really good; this bines the difficulties of both without enjoying th e same title, by Dr. Sutton Pippard and in spite of some of the ablest of the experimental the advantages of either. Captain Pritchard, issued as a "Secret and work described in the two volumes, by Dr. G. P. Confidential" publication by the Technical Of a total of nearly 950 pages in the two Douglas and Mr. Perring (1086, 1091, 1123, Departmen t of the Aircraft Production Section volumes less than 100 deal with engines and 1124, 1134). of the Ministry of Munitions in February, 1918. only some 65 with purely internal combustion problems, as distinct from the inter-relation The price of this edition is in striking contrast On the other hand we have an outstanding of engine, airscrew, and aircraft. One may t o the guinea asked for the second edition, instance of happily conceived theoretical work presume that with the concentration of our issued in 1924. In accordance with current acting as a guide to fruitful experiment, in the practice, it is in loose-leaf form, suitable for the resources on the problems of compression igni treatmen t of the autogyro by Mr. Glauert reception of additions and modifications. (1111) and Mr. Lock (1127), and another in tion later volumes will show a readjustment Mr. Lock's airscrew-body interference investi of these proportions. Contents : Preface, List of Drawings and gation (1120), containing the germ of his recent The reports under the heading of "Materials " Dat a required for strength calculations. Sum paper before the Royal Aeronautical Society. (apart from Mr. Brazier's noted above) are mar y of cases to be considered in calculating Of the essentially suggestive work probably of general rather than of purely aeronautical th e strength of the various components of the th e most interesting is Mr. Brazier's on the interest, as indeed must be true of all such structur e of an aircraft. Chapter I, The Loads stresses in beams of thin sheet metal (1081). work. Dr. Gough extends his researches on the upon an Aircraft. Chapter II, Method of I t is perhaps unfortunate that its style is so behaviour of metals under varying stress to a Calculation of Forces on Main Plane Structure. Chapter III, Strength of Main Plane Structure. condensed. That the author is no longer "singl e crystal " specimen of iron (1148). As Chapter IV, Forces on and Strength of Fuselage. engaged in work of this kind is a matter for with simpler types of stress, the ability to regret. The subject is one which needs all the experiment on "single crystals" promises Chapter V, Tail Unit. Chapter VII , Miscellane strength that we can bring to it. In the same to give us an insight into the mechanism of the ous Parts of an Aircraft and Points in General class are Professor Jones' "streamline aero distortion of metals which no work confined Design. Chapter VIII, The Aerdynamic Load plane " work (1115), (which led directly to his to ordinary "poly-crystal" specimens could Distribution on Tapered and Twisted Wings. paper to the R.Ae.S. in January, reproduced ever hope to afford. Appendices I-XVI. in the April issue of this journal) and Mr. In addition to the items mentioned above, Excep t for certain amplifications and a con McKinnon Wood's investigation of the advan which arc probably those of outstanding siderable increase in the number of diagrams tages of supercharging (1112). technical interest, we have the report (1149) and graphs, there is little change from the of the Scale Effect Panel, blessing the Variable previous edition. The second portion of the Those interested primarily in aeroplane Density Tunnel, now under construction, as a Preface appears, however, to be new matter, design will find much of definite usefulness in these volumes. Apart from matters of means of determining in particular the maxi as docs the whole of Chapter VIII, describing detail, of which there is no lack, we have Mr. mu m lift of aerofoils at full scale Reynolds' th e new method of calculation to replace the Steven's and Mr. Nutt's account (1140) of the number. The diagram attached to the report obsolete "Stri p Theory." Chapter VI, which methods of performance testing in use at is a summary of the outstanding features of in former editions covered undercarriages, is Figs. 1, 2 and 3 of the following report (1122) Martlesham. It is a relief to find this matter omitted, but this will no doubt be issued later which describes the work carried out by the dealt with in so straightforward a manner. in a form suitable for insertion.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Mar 1, 1929