Progress in Aeronautical Sciences 9. [antikvár]

PREFACE The present, ninth, volume in this series begins with a very welcome contri-bution to our knowledge in the field of aircraft structures. It is the first article concerned with the vibrational characteristics of certain aircraft and supplements the comprehensive account of mátrix methods of structural analysis given in Volume 4 (Argyris, 1964). Written by two well-known workers in this field, the article gives an authoritative account of the present position. The second article is a very substantial contribution to a new field of work which is concerned with the application of modern computer methods to fluid mechanics. The case treated is that of three-dimensional supersonic flows. In a way, this supplements the extensive review, in Volume 8 (Hess and Smith, 1967), of methods for calculating potential flows about arbitrary bodies, but the solution of the problems treated in the present article would seem to need even more the powers of modern numerical methods. The editors are particularly pleased to have this article contri-buted by one of the pioneers in this field of work, who himself did so much to bring about its rapid progress. It is most remarkable how work in the field of boundary layers keeps expanding and how ever new aspects appear. Whereas the fundamentals of turbulent boundary layers in incompressible flows and alsó generál three-dimensional flows were extensively reviewed in Volume 2 (Rótta; and Cooke and Hall, 1962) and boundary layers in rarefied gas flows in volume 8 (Wuest, 1967), the third article in this volume is devoted to practical methods for calculating heat transfer in hypersonic flow. This highly topicai subject is naturally, more than others, in a state of flux. It is treated here by one of the foremost workers in this field in a personal and highly illuminating manner. As indicated in the Preface to the preceding volume, we return here again to the subject of magnetohydrodynamics in a review of somé fluid-dyna-mic aspects of M. H. D. power generators, to supplement a previous contribution in Volume 8 (Gold, 1967). This new field of endeavour has been called "a blend of the two classical and somewhatexhausted disciplines of electromagnetism and fluid mechanics" (Shercliíf) and, while onemight