Acoustic testing is crucial in the aero-engine design process, providing valuable information about the sound field in terms of acoustic modes. The conventional use of a uniform sampling array limits the achievable resolution for a given number of sensors, necessitating the use of a large number of sensors to achieve high-resolution estimates. This limitation may be overcome using a non-uniform sensing array. In this work, we propose an optimal microphone selection scheme to determine which microphone placements that are preferable given the typically available a priori knowledge of the relevant acoustic modes. Using a weighted A-optimality criterion, we formulate the sensor selection problem as the one minimizing the expected variance of the resulting parameter estimates. Using both numerical and measured data sets, we illustrate how the proposed scheme allows for improved performance as compared to random and uniform sensor placement schemes.

中文翻译：

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航空发动机声学测量的最佳麦克风选择

声学测试在航空发动机设计过程中至关重要，可以提供有关声学模式声场的宝贵信息。均匀采样阵列的常规使用限制了给定数量的传感器可实现的分辨率，因此需要使用大量传感器来实现高分辨率估计。使用非均匀感测阵列可以克服该限制。在这项工作中，我们提出了一种最佳麦克风选择方案，以确定在相关声学模式的通常可用的先验知识的情况下优选哪些麦克风放置。使用加权 A 最优标准，我们将传感器选择问题表述为最小化结果参数估计的预期方差的问题。使用数值和测量数据集，我们说明了与随机和均匀传感器放置方案相比，所提出的方案如何提高性能。