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Vortex Induced Vibration what is it? when does it occur?. Relative Flow. VIV?. Atmospheric VIV - Guadeloupe. Relative Flow. Vortex Shedding Forces. Vortex shedding generates alternating forces f v = (S.U)/d ~ 0.2.(U/d). Lock-On. What happens if f v = f n ?. a/D. 1. 0. 1.
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Vortex Induced Vibration what is it? when does it occur? Relative Flow VIV?
Relative Flow Vortex Shedding Forces • Vortex shedding generates alternating forces • fv = (S.U)/d ~ 0.2.(U/d)
Lock-On • What happens if fv = fn ? a/D 1 0 1 fv/fn
Predicting VIV • Hand Calculation - Strouhal Analysis • Numerical Methods (OrcaFlex VIV Toolbox) • Frequency Domain (Shear7, VIVA) • Time Domain (Wake Oscillators, Vortex Tracking) • CFD (including structural model)