Damping and source strength characteristics of corrugated pipes: influence gap width

To be able to predict the onset of flow induced pulsations in real risers, with variations in corrugation geometry and process conditions along the risers, a set of experiments was done with a variation of gap width and Reynolds number. In addition to configurations with constant cavity geometry also a geometry was tested in which the gap width varied. The damping, source strength and onset were determined via passive damping experiments and flow tests. The source strength was proportional to the (gap width)1.55 and with the Reynolds number according (1+M)Re0.25. The measured source strength of the varied geometry could be reconstructed from the power curves of individual cavities. That means no hydrodynamic interaction between cavities was observed in the geometries containing a mixture of different cavity geometries