Sound characteristics of a pipe with dynamically rough boundary

Anna Romanova , Kirill Horoshenkov , Simon Tait

Observing the acoustic field in the pipe above a dynamically rough water surface can provide a better understanding of the hydraulic roughness patterns and the change in these patterns which are caused by the hydraulic turbulence interacting with pipe wall roughness. This work presents results from a novel experimental setup, which allows for simultaneous measurements of the acoustic field in the pipe and water surface behavior. The acoustic and hydraulic characteristics were studied under controlled laboratory conditions, where six hydraulic regimes were used with a rough pipe bed condition. The acoustic technique makes use of acoustic Gaussian pulse which is transmitted in air above the turbulent water in the pipe. The scattering of the pulses was recorded on four non-equidistantly spaced microphones. The results obtained for the six flow regimes demonstrate that the statistical properties of the acoustic field are linked to the statistical properties of the dynamically rough water surface. This study demonstrates that the cross-correlation function of the four microphone pairs and the frequency spectrum statistics can be used for the flow water level and surface waves airborne measure. Statistical analysis methodology for the above techniques is briefly described.

Mots clés: gaussian pulse; dynamic roughness; water surface; continuous wave

Domaines: Acoustique [physics.class-ph]

Anna Romanova, Kirill Horoshenkov, Simon Tait. Sound characteristics of a pipe with dynamically rough boundary. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810579⟩