Acoustics of Fluid Filled, Small Cavities: Theoretical Models and Applications

The purpose of this paper is to present the main developments in the theory of the acoustics of dissipative uids at rest in hounded spaces (principally cavities of different sizes and shapes), from the early beginnings (in the 1850 s) until now, including a brief indication of possible approaches for future developments.Several applications of interest.and current research concerned with miniaturisation, are presented, with emphasis being given to the work done on the acoustic gyrometer and on its potential to be miniaturized, which includes the miniaturiution of acoustical transducers (on silicon chips). l. lNTRODUCTlONThe aim of this paper is to outline the main developments towards obtaining a description of the linear, dynamic behaviour of viscous heat-conducting compressible uids at rest.It will deal with bounded spaces in general but focus particularly on small cavities and thin fluid layers, For more than 100 years, there has been a very strong motivation to get a good description of wave propagation in tubes.which takes into account the dissipative effects, as a lot of well known applications require good theoretical models for waveguides (including the widely used capillary tubes).In addition, since the early 1930's there has been increasing attention given to small cavities, particularly for the design and calibration of transducers [l,2,3,4,5,6], and since the research (section 4).