openPSTD: the open source pseudospectral time-domain method for acoustic propagation

An open source implementation of the Fourier pseudospectral time-domain (PSTD) method for computing the propagation of sound is presented, which is geared towards applications in the built environment. Being a wave-based method, PSTD captures phenomena like diffraction, but maintains efficiency in processing time and memory usage as it allows to spatially sample close to the Nyquist criterion, thus keeping both the required spatial and temporal resolution coarse. In the implementation it has been opted to model the physical geometry as a composition of rectangular two-dimensional subdomains, hence initially restricting the implementation to orthogonal and two-dimensional situations. The strategy of using subdomains divides the problem domain into local subsets, which enables the simulation software to be built according to Object-Oriented Programming best practices and allows room for further computational parallelization. The software is built using the open source components, Blender, Numpy and Python, and has been published under an open source license itself as well. For accelerating the software, an option has been included to accelerate the calculations by a partial implementation of the code on the Graphical Processing Unit (GPU), which increases the throughput by up to fifteen times. The details of the implementation are reported, as well as the accuracy of the code.

本项研究提出了一种开源的傅里叶伪谱时域（PSTD）方法，用于计算声音的传播，该方法特别适用于建筑环境中的应用。作为一种基于波的方法，PSTD能够捕捉诸如衍射等现象，同时在处理时间和内存使用效率上保持高效，因为它允许空间采样接近奈奎斯特标准，从而保持所需的空间和时间分辨率相对粗糙。在实现过程中，选择将物理几何建模为二维矩形子域的集合，因此最初将实现限制在正交和二维情况。采用子域的策略将问题域划分为局部子集，这使得模拟软件能够根据面向对象编程的最佳实践构建，并为进一步的计算并行化提供了空间。该软件采用开源组件Blender、Numpy和Python构建，并且本身也以开源许可证发布。为了加速软件，还包含了一种选项，即通过部分代码在图形处理单元（GPU）上的实现来加速计算，从而将吞吐量提高高达十五倍。此外，还报告了实现细节以及代码的准确性。