Acoustic wave propagation in a pipe with fully developed turbulent flow

Abstract The flow disturbance caused by fittings in a pipe generates an intense internal sound field which propagates throughout the piping system. It excites the pipe wall vibrations which in turn generate external sound. The pressure and velocity spectra (Agarwal, PhD Thesis, 1985) of the internal sound field show a strong plane wave component at low frequencies and the presence of higher order acoustic modes at the higher frequencies. Thus, in the study of external noise radiation from piping systems excited by the internal wall pressure field, it is important to know the propagational characteristics of both axisymmetric and asymmetric acoustic modes. Most of the earlier studies of propagation of sound in circular ducts are limited to the use of a mean-velocity distribution given by a power-law with uniform flow in the core. In this paper, theoretical results are presented for sound propagation in a hard walled pipe with a fully developed turbulent flow profile.