Uogólniony opis średniego ciśnienia akustycznego w quasiliniowym przybliżeniu parabolicznycznym

Harmonic generation in the nearfield of the harmonically excited cireular piston souree is considered. The quasilinear parabolic model is used to determine the averaged pressure over the planar receiving transducer of a diameter equal to that of the souree. The model is then simplified by assumption that the receiving transducer covers the entire section of the aeoustie beam. The derived general expressions are used in sample computations of the second and third harmonie eomponents of the averaged pressure in distilled water. The resuLts ofcomputations are eompared with the results obtained from direct numerical integration (so ealled Bergen eode) of the KZK equation and with the experiment conducted in distilled water.