Statistics of phase fluctuations of an acoustic wave propagating through a turbulent flow

TL;DR

This paper studies how turbulence affects the phase of acoustic waves, combining experiments and a geometrical acoustics model to analyze phase fluctuation statistics in a controlled turbulent flow.

Contribution

It introduces a model for phase fluctuations of acoustic waves in turbulent flow and validates it with experimental data.

Findings

RMS and PSD of phase fluctuations match model predictions

Experimental data confirms geometrical acoustics model accuracy

Flow conditions are well-controlled and consistent with theoretical assumptions

Abstract

We investigate the statistics of phase fluctuations of an acoustic wave propagating through a turbulent flow in line of sight (LOS) configuration. Experiments are performed on a closed von Karman swirling flow whose boundaries are maintained at a constant temperature. In particular, we analyze the root mean square (RMS) and the power spectrum density (PSD) of phase fluctuations. A model is developed and analytical predictions obtained for these quantities using geometrical acoustics are shown to be in agreement with experimental observations.