Pavlov, V. and Tito, E. P. (2009) Transition scattering in stochastically inhomogeneous media. Journal of the Acoustical Society of America, 125 (2). pp. 676-689. ISSN 0001-4966 http://resolver.caltech.edu/CaltechAUTHORS:20090420-075600971
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When a physical object (“a source”) without its own eigenfrequency moves through an acoustically homogeneous medium, the only possible form of acoustic radiation is the emission of Mach shock waves, which appear when the source velocity surpasses sonic speed. In nonhomogeneous media, in nonstationary media, or in the neighborhood of such media, the source motion is accompanied by the so-called “transition” radiation (diffraction or scattering), which has place even when the source moves with subsonic velocity. Key features pertaining to the formation of the acoustical transition scattering in media with fluctuating acoustical parameters are established. To analytically study the effect, the Green's function method formulated in terms of functional derivatives is used. The relationship between the wave number and frequency, k=k(ω), for acoustic waves is found. The results serve to determine the phasing conditions necessary for opening the transition scattering and Cherenkov radiation channel and to establish the physical explanation for the phenomenon—scattering (transformation) on inhomogeneities of the accompanied source field; i.e., formation of radiation appears when the attached field readjusts back to the equilibrium state after being deformed while passing through the fluctuations of the medium.
|Additional Information:||© 2009 Acoustical Society of America. Received 30 April 2008; revised 3 November 2008; accepted 6 December 2008.|
|Subject Keywords:||acoustic wave scattering; Cherenkov radiation; inhomogeneous media; Mach number; shock waves|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||20 Apr 2009 17:37|
|Last Modified:||26 Dec 2012 10:58|
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