Spectrum of High-Frequency Acoustic Noise in Inviscid Liquid-Linear Approximation for Spherical Waves

Abstract

The high-frequency asymptotics of the acoustic noise spectrum is considered for the case of spherically symmetric waves propagating in an unbounded inviscid liquid. Using the Kirkwood and Bethe hypothesis regarding kinetic enthalpy, the Euler equations, the equation of state in the Tait’s form and following linearization allow the kinetic enthalpy and “reduced” pressure to be obtained. The Fourier transform yields the spectral density of acoustic energy which proves to be inversely proportional to the square frequency and decreases approximately by 6 decibels per octave with increase of a frequency.