Slender structures immersed in a cross flow can experience vibrations inducedby vortex shedding (VIV), which cause fatigue damage and other problems. VIVmodels in engineering use today tend to operate in the frequency domain. A timedomain model would allow to capture the chaotic nature of VIV and to modelinteractions with other loads and non-linearities. Such a model was developedin the present work: for each cross section, recent velocity history iscompressed using Laguerre polynomials. The compressed information is used toenter an interpolation function to predict the instantaneous force, allowing tostep the dynamic analysis. An offshore riser was modeled in this way: Someanalyses provided an unusually fine level of realism, while in other analyses,the riser fell into an unphysical pattern of vibration. It is concluded thatthe concept is promissing, yet that more work is needed to understand orbitstability and related issues, in order to further progress towards anengineering tool.
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