Vorticity and temperature fluctuations measurements, using
ultrasound scattering
The scattering of sound waves by inhomogeneous has lead to the development acoustic spectroscopy of flow structures in much the same way as light spectroscopy can be used to probe matter organisation. Indeed, acoustic waves couple with both the density variations and the velocity gradients of the flow. In the case of velocity gradients it can be shown the vorticity field alone contributes.
We report experimental studies that show how the scattering of a incoming sound wave by a an inhomogeneous flow yields a non intrusive and spectral measurement of the vorticity and temperature fields in high Reynolds number flows. Measurements are performed in gases and liquids, including liquid gallium. Tests in liquid sodium are underway.
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