| 释义 |
hypersonic, a.|haɪpəˈsɒnɪk|
[f. hyper- + sonic a., after supersonic, ultrasonic.]
1. Of, pertaining to, or designating sound waves or vibrations with a frequency greater than about 1000 million Hz. (Cf. ultrasonic a.)
1937B. V. R. Rao in Nature 22 May 885/1 Spontaneously existing sound-waves of thermal origin of very high frequencies (‘hyper-sonic waves’). 1938― in Proc. Indian Acad. Sci. A. VII. 163 It appears desirable to designate the portion of the acoustic spectrum having a frequency higher than a thousand mega-cycles per second as the ‘hyper-sonic’ region, while the ‘ultra-sonic’ region may be taken to extend from one to a thousand mega-cycles per second. 1948Rep. Progress Physics XI. 205 Workers in India particularly have used hypersonic to denote ultrasonic phenomena (of thermal origin) at frequencies of the order of 1000 Mc/sec. or higher. 1960Physical Rev. CXVII. 1248 The hypersonic absorption was studied for longitudinal and transverse waves at various frequencies up to 4000 Mc/s. 1963J. Blitz Fund. Ultrasonics vi. 167 Bömmel and Dransfeld measured the attenuation of both longitudinal and shear waves in quartz at frequencies ranging from 1,000 to 4,000 Mc/s using a hypersonic technique. 1971Nature 24 Sept. 238/2 Mechanical surface waves can now be generated up to 10 GHz. Mechanical waves of these frequencies (up to 100 GHz) are often termed hypersonic.
2. Involving, pertaining to, capable of, or designating speeds greater than about five times the speed of sound. (Cf. supersonic a.)
1946Jrnl. Math. & Physics XXV. 247 Hypersonic flows are flow fields where the fluid velocity is much larger than the velocity of propagation of small disturbances, the velocity of sound. 1958Engineering 14 Mar. 347/2 Flow about bodies at subsonic, supersonic, and hypersonic speeds. 1958Times 19 Dec. 11/7 Hypersonic travel is just possible in the foreseeable future. 1960New Scientist 14 July 88/2 The hypersonic wind tunnel is almost more necessary than the supersonic... A tunnel capable of producing..air speeds between Mach 10 and Mach 27 (something near 18,000 m.p.h.) is now in daily use. 1960Nature 6 Feb. 346/2 The transition from the supersonic to the hypersonic régime occurs at a Mach number of about 5, but all the characteristic features of the latter régime may only become well developed at a much higher Mach number of, say, 15. 1969Courier Mail (Brisbane) 17 Apr. 2 The construction of a 500-seat hypersonic aircraft could cost as much as {pstlg}4000 million. |