Author Bridge, C., Willis, N., Sworn, A. and Wilde, J. de
Title Development of SHEAR7 Lift Curves for VIV Analysis and Application to Single Pipe and Bundle Risers
Conference/Journal Offshore Technology Conference (OTC), Houston
Paper no. OTC2005-17533
Month May
Year 2005

In late 2003 BP contracted 2H to manage and run a series of forced oscillation tests at the Marin test basin, Netherlands. The tests examined the effect of vortex induced vibration (VIV) and galloping response on a full size section model of a single pipe riser and a non-symmetric riser bundle. The tests used a 200mm diameter pipe at a Reynolds number of 40,000.
This paper presents the results (lift and added mass coefficient with increasing amplitude and reduced velocity) from the single pipe forced oscillation tests. A method is developed to convert the test data into parabolic lift curves and damping coefficients for Shear7 VIV analysis. The parabolic life curves created from the single pipe forced oscillation test data are shown. The method is then extended for use with the test data from the non-symmetric riser bundle forced oscillation tests, and accounts for differences in peak reduced velocity in the test data by calculating effective vortex shedding diameters.
Sensitivity analysis is conducted using the parabolic lift curves with Shear7 on an example deepwater riser. This shows that the fatigue lives predicted using the parabolic lift curves are generally lower than the default Shear7 lift curves.

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