论文标题
充气旋转球体的声学光谱
Acoustic spectra of a gas-filled rotating spheroid
论文作者
论文摘要
充满气体共鸣腔的声谱可用于间接探测其内部速度场。这种非常规的速度法对于不透明的流体或快速旋转的流程特别有趣，无法使用标准方法对其进行成像。这需要（i）确定足够数量的声学模式，（ii）准确测量其频率，（iii）与理论合成光谱进行比较。我们的研究依靠专用实验，一个充气的椭圆形旋转球体，我们的研究解决了这三个挑战。为此，我们使用一个全面的理论框架，以及有限元计算，并考虑对称性论点。我们表明，可以通过我们的声学测量成功检索科里奥利力的效果，从而为大量模式提供了旋转分裂（或Ledoux）系数的首次实验测量。我们的结果铺平了模态声学速度法的道路，使其成为绘制大规模流量的强大，多功能和非侵入性的方法。页：1-14
The acoustic spectrum of a gas-filled resonating cavity can be used to indirectly probe its internal velocity field. This unconventional velocimetry method is particularly interesting for opaque fluid or rapidly rotating flows, which cannot be imaged with standard methods. This requires to (i) identify a large enough number of acoustic modes, (ii) accurately measure their frequencies, and (iii) compare with theoretical synthetic spectra. Relying on a dedicated experiment, an air-filled rotating spheroid of moderate ellipticity, our study addresses these three challenges. To do so, we use a comprehensive theoretical framework, together with finite-element calculations, and consider symmetry arguments. We show that the effects of the Coriolis force can be successfully retrieved through our acoustic measurements, providing the first experimental measurements of the rotational splitting (or Ledoux) coefficients for a large collection of modes. Our results pave the way for the modal acoustic velocimetry to be a robust, versatile, and non-intrusive method for mapping large-scale flows. Pages: 1-14
