Atmospheric sound propagation in a moving fluid above an impedance plane: Application of the semi-analytic finite element method

2021 ◽  
Vol 149 (2) ◽  
pp. 1285-1295
Author(s):  
Ray Kirby
2010 ◽  
Vol 36 ◽  
pp. 282-286 ◽  
Author(s):  
Manabu Sasajima ◽  
Takao Yamaguchi ◽  
Akira Hara

The acoustic pathway in the enclosure of small headphones is very narrow. Therefore, the speed of sound propagation and the phase change because of the air viscosity. We have developed a new finite element method that considers the effects of damping due to air viscosity in the sound pathway. The new finite element method is obtained by improving the finite element method proposed by Yamaguchi for porous sound-absorbing materials. Moreover, we have attempted to obtain a numerical calculation of damping due to air viscosity by using the proposed finite element method.


2006 ◽  
Vol 14 (04) ◽  
pp. 489-506 ◽  
Author(s):  
L. LEHMANN ◽  
S. LANGER ◽  
D. CLASEN

When studying unbounded wave propagation phenomena, the Sommerfeld radiation condition has to be fulfilled. The artificial boundary of a domain discretized using standard finite elements produces errors. It reflects spurious energy back into the domain. The scaled boundary finite element method (SBFEM) overcomes this problem. It unites the concept of geometric similarity with the standard approach of finite elements assembly. Here, the SBFEM for acoustical problems and its coupling with the finite element method for an elastic structure is presented. The achieved numerical algorithm is best suited to study the sound propagation in an unbounded domain or interaction phenomena of a vibrating structure and an unbounded acoustical domain. The SBFEM is applied to study the sound transmission through a separating component, and for the determination of the sound field around a sound insulating wall. The results are compared with a hybrid algorithm of Finite and Boundary Elements or with the Boundary Element Method, respectively.


2021 ◽  
Vol 9 (9) ◽  
pp. 956
Author(s):  
Yi-Qing Zhou ◽  
Wen-Yu Luo

The finite element method is a popular numerical method in engineering applications. However, there is not enough research about the finite element method in underwater sound propagation. The finite element method can achieve high accuracy and great universality. We aim to develop a three-dimensional finite element model focusing on underwater sound propagation. As the foundation of this research, we put forward a finite element model in the Cartesian coordinate system for a sound field in a two-dimensional environment. We firstly introduce the details of the implementation of the finite element model, as well as different methods to deal with boundary conditions and a comparison of these methods. Then, we use four-node quadrilateral elements to discretize the physical domain, and apply the perfectly matched layer approach to deal with the infinite region. After that, we apply the model to underwater sound propagation problems including the wedge-shaped waveguide benchmark problem and the problem where the bathymetry consists of a sloping region and a flat region. The results by the presented finite element model are in excellent agreement with analytical and benchmark numerical solutions, implying that the presented finite element model is able to solve complex two-dimensional underwater sound propagation problems accurately. In the end, we compare the finite element model with the popular normal mode model KRAKEN by calculating sound fields in Pekeris waveguides, and find that the finite element model has better universality than KRAKEN.


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