Wave Kinematics and Environmental Forces: Papers Presented at a Conference Organized by the Society for Underwater Technology and Held in London, U.K.

ISBN-13: 9780792321842 / Angielski / Twarda / 1993 / 346 str.

Society for Underwater Technology;Society for Underwater Technology;Society for Underwater Technology

Opis

In determining the response of offshore structures, it is of utmost importance to determine, in the most correct manner, all factors which contribute to the total force acting on these structures. Applying the Morison formula (Morison et. al., 1950) to calculate forces on offshore slender structures, uncertainties related to the understanding of the wave climate, the hydrodynamic force coefficients and the kinematics of ocean waves represent the most important contributions to the uncertainties in the prediction of the total forces on these structures (Haver and Gudmestad, 1992). Traditional calculation of forces on offshore structures involves the use of regular waves with the following non-linearities inco1porated use of regular wave theories inco1porating higher order terms use of Morison equation having a nonlinear drag term inclusion of the effect of the free surface by integrating all contributions to total forces and moments from the sea floor to the free surface of the waves In order to describe the sea more realistically, the ocean surface is to be described as an irregular sea surface represented by its energy spectrum. The associated decomposition of the sea surface is given as a linear sum of linear waves. The total force is found by integrating the contribution from all components in the wave spectrum to the free surface. The kinematics of each component must therefore be determined.

Spis treści

Session One: Wave Kinematics. 1. Technical Update and Field Data from the New Generation Microwave Directional Wave Radar; S.J. Archer. 2. Wave Kinematics, Measurement, Modelling and Application; J.S. Buchan. 3. Nonlinear Wave Current Interactions; I. Cummins, C. Swan. 4. Effects of a Shear Current on Wind Induced Waves; A.K. Magnusson. 5. Uncertainties in Prediction of Wave Kinematics in Irregular Waves; O.T. Gudmestad, S. Haver. 6. Wave Kinematics on Sheared Currents; D.J. Skyner, W.J. Easson. 7. Laboratory Wave Generation Correct to Second Order; H.A. Schäffer. Session Two: Fluid Loading. 8. Comparison of Loads Predicted by a New Wave Theory with Measurements on the Tern Structure; J. Rozario, P.S. Tromans, M. Efthymiou, P.H. Taylor. 9. Wave Loading Model Tests on a Gravity Base Structure; J.J. Murray, L.M. Mak. 10. Added Hydrodynamic Loading Due to Sacrificial Anodes; M.J. Downie, B.A. Murray, P. Bettes. 11. The Vortex Induced Vibration of Marine Risers in Sheared and Critical Flows; G. Jones, W.S. Lamb. 12. Suppression of Vortex Shedding from Satellite Risers in a Current; M.M. Zdravkovich, J.l. Baldaro. Session Three: Coastal Conditions. 13. Review of Wave Breaking in Shallow Water; H.N. Southgate, H.R. Wallingford. 14. Three-Dimensional Breaking Wave Kinematics; K. She, C.A. Greated, W.J. Easson. 15. Environmental Forces at the Coastline and Implications for Coastal Defence; N.W. Beech, J.L. Andrews. 16. Full Field Study of Post Breaking Vorticity; S.Lloyd, C.A. Greated, W.J. Easson. 17. Multigrid Model of Wave-Current Interaction; Bin Li. 18. Variation in Beach Profiles in Hell's Mouth Bay, Llyn Peninsula for the Period 1979-1981; J. Darbyshire.