Corrugated pipes combine small-scale rigidity and large-scale flexibility, which makes them very useful in industrial applications. The flow through such a pipe can induce strong undesirable whistling noises and even drive dangerous structural vibrations. Placing a short corrugated segment along a smooth pipe reduces the whistling, while this composite pipe still retains some global flexibility. The whistling is reduced by thermo-viscous damping in the smooth pipe segment. A linear semi-empirical model is proposed that allows to predict the critical Mach numbers at the onset of whistling for a composite pipe at moderately high Reynolds numbers. Experimental results for corrugated pipes of three different corrugations geometries are presented revealing fair agreement with the theory. In addition, the model indicates that even for a corrugated pipe segment with an anechoic termination, corresponding to a very long smooth pipe segment, there exists a finite critical Mach number above which the whistling occurs.

This content is only available via PDF.
You do not currently have access to this content.