Aircraft wake turbulence and airport capacity.
J. D. Jacob, D. Liepmann, and Ö. Savas
Institute of Transportation Studies Review, University of California,
Berkeley,
1996, 19(4).
The science of flight has come a long way since that gusty day in December, 1903 when Orville Wright made the first sustained powered flight in the history of mankind. In the brief time since then, engineers and inventors have made leaps and bounds in taming the sky for the average traveler. Long gone are the days of the rickety, noisy, and dangerous open cockpit planes. The aircraft industry changed quickly in the first few decades of existence, thrust ahead with the spirit of numerous pioneers and entrepreneurs. Henry Ford with designer William Stout was instrumental in making the airplane safe and relatively inexpensive with the all-metal design of the Ford Tri-Motor (aka the Tin Goose) and marketing it with fledgling airlines and the construction of the first airports with concrete runways. (It was even Ford who came up with the idea of putting the airline crew in uniforms to make the novelty appear more legitimate.) Along the way history was made with aviation milestones such as the versatile DC-3, the pressurised Stratoliner, the jet-powered Comet, the wide-body B-747, the supersonic Concorde, and more recently, the first jet for the 21st century, the Boeing 777. The airplane and the airport have became an integral part of the nation's transportation infrastructure, second only in visibility to the highway system. Travel by air is the most efficient mode of modern travel and still one of the safest. The estimated cost per passenger mile is approximately 5 cents while travel by car can be up to ten times that figure. The air travel system has three main components: the airport, the airplane, and the airline. Each has an equal priority and all three must be operating fully and harmoniously to keep the system running smooth. The vortex wake is a physical problem of great interest to a variety of disciplines, including aeronautical engineers, air traffic administrators, aircraft manufacturers, and pilots. It has recently become more visible to the public due to interest in the cause of some aircraft accidents which have been partially attributed to the action of the vortex wakes, though from a purely scientific standpoint, the level of interest in this problem has been high since the inception of aircraft. Recently, joint experiments between government agencies and a major aircraft manufacturer were conducted to study the vortex wake and its role in recent accidents. This renewed interest can also be accredited to better methods of experimental and numerical investigation which have been developed in the last ten years which include field techniques that allow the capture of instantaneous velocity fields in a single plane.