| Popis: |
On the basis of processing algorithms developed by the same authors in a companion paper [“On the general connection between wave impedance and sound intensity”, 173rd Meeting of the Acoustical Society of America and the 8th Forum Acusticum, Boston MA, 25-29 June 2017] where the equation between the complex sound intensity and the specific acoustic impedance/admittance has been stated and numerically validated in general form, the block diagram of a possible device for precision measurement of 3D spectral intensity is proposed here. In order to test its functionality, some measurements have been carried out, inside a tube of 28x28 cm2 square section and 4 m long, which was terminated with panels of different materials. Measurements have been carried out at different positions along the tube's axis by means of a 3D pressure-velocity probe below and above the cutoff frequency of the tube so to include also the effects of transversal modes. Preliminary results of such measurements are reported and discussed ... |
