Despite the fact that aircraft are commonplace there is still something magical about flight. To see a large, heavy airliner rise majestically from the runway is still surprising. And to cap it all there is space travel, with moon visits and Mars landings already accomplished. Yet it is less than 100 years since the Wright brothers achieved the first heavier-than-air, powered, manned flight, though of course there had been a slow growth of relevant knowledge dating back to Archimedes. The way in which experiment, theory and more recently the computer, have made these enormous achievements possible, is the subject of this fascinating book.
John Anderson, professor of aerospace engineering at the University of Maryland, has written a whole series of books on theoretical aerodynamics and has also spent a sabbatical year at the Smithsonian National Air and Space Museum. His dual loves of aerodynamics and history have happily coalesced in this book, which is non-technical and will appeal to anyone interested in aircraft and the way they have evolved.
The book uses a mix of both the chronological and thematic approaches. Each of the nine chapters covers a certain chronological period but they are grouped into four parts. Within each part a particular, representative flying machine is identified and discussed. The book shows how much or how little of the contemporary knowledge of aerodynamics was applied to the aircraft examples chosen.
This "mixed" presentation of material inevitably leads to repetition which is particularly noticeable if the book is read straight through. Conversely the repetition means that each part is to some extent self-contained which makes the book easier to refer to.
Part one covers the period 350BC (Aristotle) to 1804 (Cayley), but the emphasis is on the last 200 years describing the contributions of Galileo, Da Vinci, Newton, Pitot and Smeaton, among others. The outstanding work of Cayley in building successful gliders is used to demonstrate the recurring theme of the great gulf between experiment and theory.
Part two continues the story from Lilienthal to Langley ie 1800-1900. Although this period saw the publication of the theoretical work of Navier, Stokes, Helmholtz, Kirchoff and Lord Rayleigh, it was the growing body of experimental data that enabled practical machines to be built.
Part three begins with the Wright brothers. They started by examining most of the available experimental data but discovered much of it was misleading, so they carefully and systematically made their own experiments. They went on to design a highly efficient airframe with an excellent system of controls, develop propellers with greatly increased performance and build a light-weight petrol engine to power their "Flyer". All this in seven years - one can only marvel.
The second chapter of part three shows how Lanchester, Prandtl, Kutta and Joukowski produced useful theories for the development of lift and drag on real wings. These were major breakthroughs in closing the gap between theory and experiment.
The final part of the book covers 20th-century aerodynamics. Since the Wright brothers' aircraft, there have been enormous developments in aircraft aerodynamics. The Wright Flyer flew at about 10mph. Most readers of this book will have flown at 500mph. Concorde routinely reaches more than 1300mph. For me this part of the book is the most exciting. It is good to see Eiffel given due recognition. He did much, much more than build a tower in Paris. The major developments of the past 100 years include streamlining, the development of wind tunnels for accurate model testing, the understanding and solution of problems associated with the "Sound Barrier" and the advent of supersonic flight. Again recent history is shown to be a mixture of brilliance, ignorance, invention and inspiration. It is incredible that the advantages of sweep-back, clearly explained at a conference in 1935, were overlooked by America and the UK until 1945.
The book comes right up to date with very brief descriptions of very high speed (hypersonic) flight and the role of the computer in solving the complex flows around modern aircraft and missiles. It is intriguing to realise that the equations giving our best mathematical description of airflow around an aeroplane were formulated by Navier and Stokes before 1850, but they are only now yielding engineering answers using the most powerful computers available.
The most recent parts of history are always difficult to write about because not all the advances are well documented. Hence the later chapters tend to emphasise American achievements. The greatest omission is any mention of Whittle and Von Ohain. It was their invention of the jet engine that has transformed air travel and made supersonic flight possible. However, the omission is understandable because the book concentrates on airframes and external aerodynamics. In summary, this is an excellent book that deserves a very wide readership. But at £60 it will be the library copies that will be well thumbed. Let us hope a paperback version appears soon.
John L. Stollery is emeritus professor, College of Aeronautics, Cranfield University.
A History of Aerodynamics and its Impact on Flying Machines
Author - John D. Anderson, Jr.
ISBN - 0 521 45435 2
Publisher - Cambridge University Press
Price - £60.00
Pages - 478