J.A.F. Santiago¹, L.C. Wrobel²

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 73-80, 2000, DOI:10.3970/cmes.2000.001.375

Abstract This work presents a boundary element formulation for two-dimensional acoustic wave propagation in shallow water. It is assumed that the velocity of sound in water is constant, the free surface is horizontal, and the seabed is irregular. The boundary conditions of the problem are that the sea bottom is rigid and the free surface pressure is atmospheric.
For regions of constant depth, fundamental solutions in the form of infinite series can be employed in order to avoid the discretisation of both the free surface and bottom boundaries. When the seabed topography is irregular, it is necessary to divide the… More >

C. S. Iorio¹, C. Perfetti¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.1, pp. 27-48, 2015, DOI:10.3970/fdmp.2015.011.027

Abstract In the past few years, modeling of the Acoustic StandingWaves (ASW) phenomena has become a topic of great interest due to its theoretical connections with particle/cells manipulation techniques, which represent important tools in the biotechnology field. The present paper proposes a model based on the use of moving wall boundary conditions coupled with a viscous compressible fluid in a square channel. This model successfully achieved the generation of ASWs in the square cross-section for several resonance frequencies; the corresponding acoustic potential for the fundamental resonant mode and several harmonics have also been calculated and are discussed here. More >

M.K. Achour¹, S. Kaddeche², A. Gharbi², H. Ben Hadid³, D. Henry³

FDMP-Fluid Dynamics & Materials Processing, Vol.1, No.4, pp. 277-284, 2005, DOI:10.3970/fdmp.2005.001.277

Abstract The effects of an acoustic wave on the instabilities occurring in a lateral differentially heated cavity are investigated numerically. Linear stability results show that the acoustic wave affects significantly the instability characteristics of such a Hadley flow. Indeed, the sound field is found to stabilize both two dimensional transverse stationary and three dimensional longitudinal oscillatory instabilities which are the most critical modes affecting the buoyant convection in the fluid layer. Nevertheless, when stabilized by an acoustic wave, the 2D modes turn from stationary to oscillatory, with the known consequences of such a change on mass and heat transfer, especially in… More >

Carlos J. S. Alves, Pedro R. S. Antunes¹

CMC-Computers, Materials & Continua, Vol.2, No.4, pp. 251-266, 2005, DOI:10.3970/cmc.2005.002.251

Abstract In this work we show the application of the Method of Fundamental Solutions(MFS) in the determination of eigenfrequencies and eigenmodes associated to wave scattering problems. This meshless method was already applied to simple geometry domains with Dirichlet boundary conditions (cf. Karageorghis (2001)) and to multiply connected domains (cf. Chen, Chang, Chen, and Chen (2005)). Here we show that a particular choice of point-sourcescan lead to very good results for a fairly general type of domains. Simulations with Neumann boundary conditionare also considered. More >