ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

1pPA9. Sonic-boom noise penetration into the ocean: 1995 update.

Victor W. Sparrow

Grad. Prog. Acoust., Penn State Univ., 157 Hammond Bldg., University Park, PA 16802

This talk is an update to a previously given presentation [ 1850--1851 (A) (1993)] in which a first-pass model for the penetration of sonic boom noise into the ocean was described. Since that presentation was given, a number of refinements to the theory have been identified, the primary of which is the effect of aircraft Mach number on the duration of the sonic boom. The general trend for aircraft flying at a fixed altitude is that the evanescent acoustic wave underwater due to a sonic boom penetrates more deeply for increased aircraft speeds [ 159--162 (1995)]. Other refinements currently under development include appropriate initial models for sound level decay as a function of depth and for focusing and defocusing of the penetrating sonic boom noise by ``frozen'' sinusoidal and trochoidal ocean surface waves. [Work supported by NASA Research Grant NAG-1-1638.]