Abstract Silencers are widely used to attenuate unwanted noise emitted by engines, exhaust, and ventilation systems or from intermittent gas flow in pipes. In recent years, the study of noise control using optimization techniques applied to silencers has been growing. The main objective of the present work is to parametrically optimize the shape of a compact reactive silencer with a single expansion chamber, modifying its construction dimensions. Sequential and simultaneous optimizations are applied to the shapes of three reactive filter types so that their sound transmission losses are maximized over pre-established frequency ranges. The optimized reactive filters are the expansion chamber with modified surface profile, extended ducts and the bi-partition of the chamber. The optimization process is carried out with the aid of the finite element method using a formulation for axisymmetric problems and with the models being discretized with linear quadrilateral elements. The optimizations were evaluated in 16 frequency range combinations totaling 98 possible results. The results showed that both optimization techniques are efficient in improving the efficiency of silencers above the first TL drop frequency of the base model, which is composed of a single expansion chamber. However, the sequential strategy presented optimized models with more regular final shapes. In addition, the methodologies are validated using the traditional three-dimensional Finite Element Method and with the experimental verification of two optimized models.

中文翻译：

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反应式消声器的多频顺序和同时参数化形状优化

摘要 消音器广泛用于衰减发动机、排气和通风系统或管道中间歇性气流发出的有害噪音。近年来，使用应用于消音器的优化技术来控制噪声的研究一直在增长。目前工作的主要目标是参数化优化具有单个膨胀室的紧凑型反应消音器的形状，修改其结构尺寸。对三种电抗滤波器类型的形状应用了顺序和同时优化，以便在预先建立的频率范围内最大化它们的声音传输损失。优化的反应过滤器是具有改进表面轮廓的膨胀室、延长的管道和室的双隔板。优化过程是在有限元方法的帮助下进行的，该方法使用轴对称问题的公式，并使用线性四边形单元离散化模型。在 16 种频率范围组合中对优化进行了评估，总共有 98 种可能的结果。结果表明，这两种优化技术都可以有效地提高由单个膨胀室组成的基本模型的第一个 TL 下降频率以上的消音器效率。然而，顺序策略提供了具有更规则最终形状的优化模型。此外，这些方法使用传统的三维有限元方法和两个优化模型的实验验证进行了验证。