Journal of Waterway, Port, Coastal, and Ocean Engineering

An experimental study of a turbulent round jet discharged into a regular wave field is presented. The particle image velocimetry (PIV) technique was employed to measure instantaneous velocity fields of the flow. Quantitative mean and turbulence properties were obtained using ensemble- and phase-averaged methods. Both the jet potential core region and self-similar region were measured. Three different wave heights were used to examine the effect of wave steepness on the jet properties. Measurements were also taken at three different phases to examine the wave phase effect. Experimental results demonstrate that the mean jet width, turbulence intensity, and Reynolds stress increased significantly when the jet was acted on by the waves. In addition, the jet mean kinetic energy decreased whereas the turbulent kinetic energy increased when the jet was under the waves, indicating an increase in turbulence. The wave phase has an insignificant effect on the both the mean and turbulence properties. The turbulent kinetic energy budget in the self-similar region at different wave conditions was also examined. It was found that the turbulent production, advection, and dissipation terms all increase with the increase of the wave height.

A model, SandTrack, has been established to simulate movements of sand-sized particles in coastal waters within a Lagrangian framework. The model can be applied to assess the dispersal of contaminated particulate material, such as may be associated with industrial discharges or the dispersal of dredged spoil. For such applications, the Lagrangian approach is essential, as the identity of the particles is important. Although Lagrangian models that existed previously could simulate fine sediment constantly in suspension, there are certain applications, such as dealing with the movement of bed particles, in which intermittent physical processes are critical. SandTrack has been tested against field observations from the coastal waters near Dounreay, United Kingdom. The tests strengthened confidence in the model predictions and enabled appropriate values of some of the model’s main physical parameters to be set. Some features of the particle distributions simulated by SandTrack are consistent with field observations and are not achievable with simpler sediment transport models. The model’s run times are sufficiently short for simulations of particle movement in moderately large coastal areas over several decades to be practical.

The Bolivar Peninsula in Texas was severely impacted by Hurricane Ike with strong winds, large waves, widespread inundation, and severe damage. This paper examines the wave and surge climate on Bolivar during the storm and the consequent survival and destruction of buildings. Emphasis is placed on differences between buildings that survived (with varying degrees of damage) and buildings that were completely destroyed. Building elevations are found to be the primary indicator of survival for areas with large waves. Here, buildings that were sufficiently elevated above waves and surge suffered relatively little structural damage, while houses at lower elevations were impacted by large waves and generally completely destroyed. In many areas, the transition from destruction to survival was over a very small elevation range of around 0.5 m. In areas where waves were smaller, survival was possible at much lower elevations. Higher houses that were not inundated still survived, but well-built houses at lower elevations could also survive as the waves were not large enough to cause structural damage. However, the transition height where waves became damaging could not be determined from this study.

Observations of wave properties during Hurricane Ike are presented for eight temporary gauges in mean depths of 8.7–15.8 m over a 360-km section of coastline. These gauges cover both the strong (left) and weak (right) sides of the tropical cyclone, with one gauge immediately adjacent to landfall. Maximum significant wave heights are large over the entire section of the coast and reached 5.8 m near landfall but were at some locations significantly limited by the finite depths with significant wave height-to-depth ratios nearing 0.5 at landfall. Nondirectional spectral shapes changed sharply over the course of the storm, from strongly peaked profiles before landfall to much flatter, sometimes multipeaked, spectra as the hurricane came ashore. After landfall, the spectra on Ike’s strong side reverted to the sharply peaked form, whereas the weak side spectra were broader and often had multiple peaks. No waves during the storm appeared to be in equilibrium with local winds and water depths, although heights on the strong side of the storm were close.

The performance of the 60 m long seawater exchange caissons installed in the west breakwater for the Port of Jeju in Korea was assessed using field data. Measurements were made of the water level in the ponding area between the weir and caisson walls and of the water velocities in the two channels located at the bottom of the caisson for a two-month duration in winter. The measured water level and velocity were analyzed in conjunction with the wave data that was concurrently obtained. The measured landward velocity in the channel in the range of 0.0 to $0.6\mathrm{m}/\mathrm{s}$ is correlated to the measured water level and wave conditions. The velocity of the order of $0.1\mathrm{m}/\mathrm{s}$ can transport a large volume of seawater from the sea side to the port side under most tide and wave conditions at this site.

A new method for estimating extreme sea levels from short sea-level records in a tide-dominated environment is presented. A short sea-level record is first decomposed into its constituent components such as tide, mean level of the sea, and storm surge. Monte Carlo simulations are then incorporated into an empirical simulation technique to randomly recombine the components to produce an annual series of sea levels at high tide from which the annual maximum is selected. The yearly simulation is repeated many thousands of times to yield robust statistics on extreme values. Comparison of the method with the traditional extreme-value analysis of annual maximum sea levels for a 33-year record shows that the methods give similar results. The method is likely to be most useful for estimation of extreme sea levels at locations where the available sea-level record is short ($<15\mathrm{years}$) and where the various sea-level components can be assumed to be largely independent.