Word: sound
(lookup in dictionary)
(lookup stats)
Dates: during 1940-1949
Sort By: most recent first
(reverse)
...designers' sights are aimed at higher things than the speeds of these sweet-flying planes. Newer models, such as North American's F-86A, are already nibbling gingerly at the speed of sound, and no one doubts that the turbojet engine can soon push properly designed airframes across the threshold...
Ghosts Know. The speed of sound! That magic and frightening quantity dominates the dreams of high-speed plane designers. It is no mere landmark, no mere handy figure for public relations officers. It is basic: the speed with which a "compression wave" (whether a faint whisper or the crushing shock wave of an atomic explosion) moves through air. The actual speed varies considerably with the air's temperature (the colder the slower). To eliminate this variability from their figuring, scientists have given the speed of sound a special name. In aerodynamics, the speed of sound in any air under...
This is why air designers approach the speed of sound with infinite trepidation. The most troublesome speed begins just below Mach I. When a wing is moving at, say, Mach .80, the air passing over it has to hurry to get around its bulge. If, in doing this, it reaches Mach I, violent things may happen. The smooth airflow breaks into turbulence as hard shock waves jump around on the wing (see cut). The drag increases enormously; the wing's lift drops. The buffeting from the irregular airflow may be strong enough to tear the wing apart. This sometimes...
...transonic" (transition) speed is the worst. After the wing gets moving well above Mach I, the air behaves reasonably again, but in a novel manner. From the leading edge of the wing, two intense sound waves flare off like the bow waves of a boat. Two more flare off from the trailing edge. If the moving object has any irregularities or sharp curves, these are apt to trail their sound waves...
Brute Plane. The only airplane, so far as is known, to fly faster than sound is the rocket-propelled X-I (TIME, Jan. 5). But the X-I is not a real operational airplane. It is very small and heavy, made largely of metal plates nearly half an inch thick. It carres no useful load except the pilot, some instruments and fuel for two minutes of flight at full power. It smashed through the transonic speed band by sheer brute force, not aerodynamic virtuosity...