Frequency Spectrum of Finite Amplitude Ultrasonic Waves in Liquids

The theory of harmonic growth for finite‐amplitude sound waves in a nondissipative fluid is discussed. The perturbation analysis of such waves in a dissipative fluid has been extended to higher orders of calculation, so that the location of the maximum of the second harmonic can be ascertained with some accuracy. The results agree well with experimental data. The effective absorption coefficient for finite‐amplitude waves also has been calculated to terms of higher order.