Water Wave Kinematics

Water wave kinematics is a central field of study in ocean and coastal engineering. The wave forces on structures as well as sand erosion both on coastlines and in the ocean are to a large extent governed by the local distribution of velocities and accelerations of the water particles. Our knowledge of waves has generally been derived from measurements of the water surface elevations. The reason for this is that the surface elevations have been of primary interest and fairly cheap and reliable instruments have been developed for such measurements. The water wave kinematics has then been derived from the surface elevation information by various theories. However. the different theories for the calculation of water particle velocities and acceleration have turned out to give significant differences in the calculated responses of structures. In recent years new measurement techniques have made it possible to make accurate velocity measurements. Hence. the editors deemed it to be useful to bring together a group of experts working actively as researchers in the field of water wave kinematics. These experts included theoreticians as well as experimentalists on wave kinematics. It was also deemed useful to include experts on the response of structures to have their views from a structural engineering point of view on what information is really needed on water wave kinematics.

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Proceedings of the NATO Advanced Research Workshop, Molde, Norway, May 22-25, 1989

Contenu
Working Group Reports.- Deep Water Wave Kinematics.- Shallow Water Wave Kinematics.- Breaking and Freak Waves.- Measurement of Wave Kinematics.- Forces.- Introductory Lectures.- Stochastic Description of Offshore Environment.- Deep Water Wave Kinematics Models for Deterministic and Stochastic Analysis of Drag Dominated Structures.- Theory versus Measurement.- Effects of Water Wave Kinematics Uncertainty on Design Criteria for Offshore Structures.- Deep Water Wave kinematics.- Slow Modulation of Weakly Nonlinear Waves.- Near Surface Irregular Wave Kinematics.- Practical Wave Modelling.- Wave Theory Predictions of Crest Kinematics.- Revision to the UK DEn guidance notes.- Conditional Simulation of Ocean Wave Kinematics and Comparison with Storm Field Measurements.- Some Aspects of the Kinematics of Short Waves over Longer Gravity Waves on Deep Water.- Irregular Water Wave Kinematics.- Computational Modelling of Velocities and Accelerations in Steep Waves.- A Viscous Modification to the Oscillatory Motion Beneath a Series of ProgressiveGravity Waves.- Short Contributions.- Application of Gaussian Wave Packets for Seakeeping Tests of Offshore Structures.- Determination of the Surface Elevation Probability Distribution of Wind Waves Using Maximum Entropy Principle.- Shallow Water Wave Kinematics.- Mathematical Modelling of Short Waves in Surf Zone.- Free and Forced Cross-Shore Long Waves.- Computation of Nonlinear Wave Kinematics During Propagation and Runup on a Slope.- Field Observations of Wave-Current Interaction at the Sea Bed.- Computation of Steep Waves on a Current with Strong Shear Near to the Surface.- Short contributions.- Kinematics of Flow on Steep Slopes.- Measurement of the Velocity and Turbulent Fields Generated by the Swell in the Vicinity of Walls or Obstacles 44l.- Breaking and Freak Waves.- Breaking Waves.- Computations of Breaking Waves.- A Comparison of Time-Stepping Numerical Predictions with Whole-Field Flow Measurement in Breaking Waves.- Transformation Characteristics of Breaking Water Waves.- Turbulence Generation in a Bore.- Freak Wave Kinematics.- Microcomputer Capabilities Numerical Simulation of a Breaking Wave.- Frequency Down-Shift Through Self Modulation and Breaking.- Extreme Waves in Laboratory Generated Irregular Wave Trains.- Advances in Impulsively Generated Water Waves.- Short contributions.- Freak Waves: a Possible Explanation.- Current-Wave Interactions Observed in the Labrador Sea Extreme Waves Experiment.- Written Discussion on Breaking and Freak Waves.- Measurements.- Flow Visualization by Vibrating Camera.- Short contributions.- Measurements of Wave Kinematics in the WADIC Project.- Measuring the Long Wave Kinematics in the PO-Waves Project.- Experimental Facility for Progressive Edge Waves.- Forces.- Morison Type Wave Loading.- The Loading on a Vertical Cylinder in Random Waves at High Reynolds Numbers.- Laboratory Waves and Associated Forces.- A Laboratory Study of the Kinematics and Forcing due to Five Similar Large Waves.- Short contributions.- Drag and Inertia Loads on Cylinders.- The Variation of the Wave Reducing Efficiency of Prismatic Fixed Surface Obstacles with Respect to its Dimensions.- Written Discussion on Forces.- Summary Paper.- * Water Wave Kinematics: State of the Art and Future Research Needs.- Index List.- List of Participants.