Design-Focused Acoustic Analysis of Curved Geometries Using a Differential Raytracing Technique
Design-Focused Acoustic Analysis of Curved Geometries Using a Differential Raytracing Technique
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使用差分光线追踪技术对弯曲几何形状进行以设计为中心的声学分析
DOI：
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发表时间：
2014
期刊：
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通讯作者：
E. Kahle
中科院分区：
文献类型：
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作者：
T. Wulfrank;Y. Jurkiewicz;E. Kahle
弯曲的表面对声音在房间中的传播有很大的影响。凸表面总是导致衰减的反射在更大的区域上传播，而凹表面产生反射的放大或衰减，这取决于源和接收器相对于弯曲表面的位置。当代建筑通常涉及大量使用凸面和凹面。因此，声学顾问需要能够快速获得对给定弯曲几何形状的透彻理解，并判断所产生的聚焦在多大程度上是良性的或有问题的（由于聚焦、不均匀的声音分布或颤动回波）。基于NURBS的3D软件（如Rhino 5）的出现使得在曲面上进行非常精确的几何光线追踪成为可能，揭示了它们的几何覆盖范围。作为进一步的改进，提出了一种差分射线追踪技术，允许直接计算由给定曲面产生的放大或衰减。这种纯粹的几何技术也可以应用于高阶反射，以帮助识别由涉及凹面的多个反射路径产生的颤振回波问题。本课程将以具有显著弯曲几何形状的大厅实例来说明这种方法的使用，包括威格莫尔大厅、伦敦和无锡大剧院。
Curved surfaces have a major influence on the propagation of sound in rooms. Convex surfaces always lead to attenuated reflections spread out over a larger area, while concave surfaces create either amplification or attenuation of reflections, depending on the source and receiver positions relative to the curved surface. Contemporary architecture often involves extensive use of both convex and concave surfaces. Therefore, acoustic consultants need to be able to quickly gain a thorough understanding of a given curved geometry, and judge to what extent the arising focusing will be either benign or problematic (due to focusing, inhomogeneous sound distribution or flutter echoes). The advent of NURBS-based 3D software (e.g. Rhino5) has made it possible to carry out very precise geometrical raytracing on curved surfaces, revealing their geometrical coverage. As a further refinement, a differential raytracing technique is proposed, allowing the straightforward calculation of the amplification or attenuation created by a given curved surface. This purely geometrical technique can also be applied to higher order reflections, in order to help identify flutter echo problems created by multiple reflection paths involving concave surfaces. Practical examples of halls with significant curved geometries will be given to illustrate the use of this approach, including Wigmore Hall, London and Wuxi Grand Theatre.