Representing arbitrary acoustic source and sensor distributions in Fourier collocation methods
Representing arbitrary acoustic source and sensor distributions in Fourier collocation methods
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DOI：
10.1121/1.5116132
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发表时间：
2019-07-01
影响因子：
2.4
通讯作者：
Treeby, Bradley E.
中科院分区：
文献类型：
--
作者：
Wise, Elliott S.;Cox, B. T.;Treeby, Bradley E.
声源分布的准确表示是超声仿真的重要组成部分。这对于基于网格的配置方法来说是具有挑战性的，当这种分布与网格点不重合时，例如当源是嵌入在三维域中的曲面时。通常，靠近震源表面的网格点被定义为震源点，但这可能导致“阶梯状”和所产生的声场中的重大误差。本文描述了一种在傅里叶配置法中精确表示任意源分布的技术。该方法通过对连续的震源分布应用离散的带限卷积算子来工作，之后可以产生震源网格权重。这允许在网格上定义任意形状的源，例如聚焦碗和圆形活塞，而不会出现阶梯错误。该技术通过对一系列超声源的模拟进行了检验，并与解析解进行了比较，结果表明该技术具有良好的精度和收敛速度。文中还讨论了该技术的扩展，包括在初值问题、分布式传感器和移动源中的应用。(C)2019年作者(S)。
Accurately representing acoustic source distributions is an important part of ultrasound simulation. This is challenging for grid-based collocation methods when such distributions do not coincide with the grid points, for instance when the source is a curved, two-dimensional surface embedded in a three-dimensional domain. Typically, grid points close to the source surface are defined as source points, but this can result in "staircasing" and substantial errors in the resulting acoustic fields. This paper describes a technique for accurately representing arbitrary source distributions within Fourier collocation methods. The method works by applying a discrete, band-limiting convolution operator to the continuous source distribution, after which source grid weights can be generated. This allows arbitrarily shaped sources, for example, focused bowls and circular pistons, to be defined on the grid without staircasing errors. The technique is examined through simulations of a range of ultrasound sources, and comparisons with analytical solutions show excellent accuracy and convergence rates. Extensions of the technique are also discussed, including application to initial value problems, distributed sensors, and moving sources. (C) 2019 Author(s).