Abstract
Measurement of the acoustic intensity (Al) flux is made in the neighborhood of a circular cylinder set normal into a circular jet flow. Results for Al flux show acceptable features only when the sensors are well out of the acoustic near-field of the sound source, that is, the cylinder. Although it can be shown analytically that Al measurement with two microphones should work well even in the near-field, measured results there show totally unacceptable features. The inevitable conclusion is that microphones inside the near-field scatter the near-field into real sound wave, and then measure it.
