A target vortex distribution can be a Karman vortex street behind a bluff body, a fluctuating wake/jet, or a more compact structure like a vortex pair. A Sell type flat sound emitter creates a plane sound wave of high frequency which interacts with the vortex field and then scatters sound in all directions. We look at a given direction by installing a Sell type flat receiver at a known scattering angle. A heterodyne detection give us the amplitude and phase of scattered pressure signals.
|
