FINITE ELEMENT AND BOUNDARY ELEMENT MODELLING FOR THE ACOUSTIC WAVE TRANSMISSION IN MEAN FLOW MEDIUM

✍ Scribed by T. TSUJI; T. TSUCHIYA; Y. KAGAWA

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 807 KB
• Volume: 255
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.2001.4189

✦ Synopsis

The frequency characteristics of the acoustic wave transmission in a medium with mean #ow are considered. One approach is to solve the Helmholtz equation with mean #ow medium in original co-ordinates, which is directly discretized for the one-dimensional and the axisymmetric FEM. Another approach is to transform the equation into the standard Helmholtz equation, which is discretized for the axisymmetric FEM and the threedimensional BEM. The numerical models are examined "rst for a straight circular duct. The solutions by the numerical approaches are compared with the analytical solution. The examination is then extended to the case when the mean #ow is locally present in the mu%er with expansion chamber. To model the spatial mean #ow in the BEM model, the partitioned domain approach is also developed. No shear e!ect between the two regions are included.