Wave flume

About: Wave flume is a research topic. Over the lifetime, 1627 publications have been published within this topic receiving 23335 citations.

Modelling sand resuspension by waves over a rippled bed

Abstract: With a two-dimensional k-ϵ model and equations to describe sediment entrainment, diffusion, convection and settling, wave-induced flow velocities and sediment concentration fields over rippled beds have been calculated. Results from the simulations are compared with time-averaged vertical suspended sediment concentration profiles, C-profiles, measured in a large wave flume using the autonomous multi-sensor instrument STABLE. The simulations make it possible to examine in detail the mechanisms of sediment entrainment, vortex formation and advection. The resulting animations of model output allow a quasi-3-D visualization of sediment resuspension processes and aid quantification of the resulting vertical suspended sediment concentration field due to regular waves, asymmetric waves and wave groups. The work contributes therefore, to knowledge about wave-sediment interactions and to understanding of sediment transport mechanics.

A laboratory investigation of wind‐generated waves

Abstract: Waves were generated by forcing wind through a covered laboratory flume. For steady-state conditions, measurements by means of an oscillograph were made of the wave characteristics at various points in the flume. The significant heights and periods were determined and related to the fetch and wind speed. The height and period of the individual waves for various fetch lengths were compared by means of joint frequency diagrams. The orbital motions of particles throughout the water depth were determined from motion pictures. Particle velocities below the crest are compared with theoretical relationships. Some information on wind set-up and shear-stress coefficients are presented.

Nearshore Sand Transport.

Abstract: : Sand transport as bedload on nearly flat beds in shallow water outside the breakers is the subject of this study. The appropriate variables necessary for computation of sediment transport are grouped into a few dimensionless force ratios using the techniques of dimensional analysis, forming a sediment transport model. Field experiments measuring fluid velocity and sand transport were performed seaward of the breaker region. Fluorescent sand tracer was used to measure both sediment-transport velocity and thickness. Thirty tracer experiments were performed under differing wave and sediment conditions. Transport thickness is well correlated with orbital diameter but not wave height or fluid velocity. Different powers of the fluid velocity are compared with sediment transport. The lower velocity moments perform much better than the higher moments. Use of a threshold criterion is essential in predicting whether the sand transport is onshore or offshore. Results suggest that the appropriate power of fluid velocity necessary for computing and transport may itself be a function of the flow intensity.

Physical modeling of the dynamics of a revetment breakwater built on reclaimed coral calcareous sand foundation in the South China Sea—tsunami wave

Abstract: In this study, taking the reclamation engineering in the South China Sea as the background, several wave flume experiments (geometrical similarity scale is set as 1:10) are performed to study the dynamics and the stability of a reclaimed calcareous sand foundation and the breakwater built on it, under the impacting of tsunami wave. Tsunami wave is similarly simulated by N wave in the wave flume. It is shown by the experimental results that the revetment breakwater has no visible displacement, and there is no significant deformation in the reclaimed coral sand foundation, regardless the foundation is in dense or loose state under tsunami wave attacking. Furthermore, there is indeed excess pore pressure generated in the reclaimed coral foundation with a maximum magnitude of 1.5 kPa, caused by the water overtopping or the seepage. It is found that the excess pore pressure has not caused liquefaction in the reclaimed calcareous sand foundation due to the fact that there is only one peak impacting for the tsunami wave-induced load, rather than a cyclic one. Finally, it is concluded that the reclaimed calcareous sand foundation and the breakwater built on it are basically stable under tsunami wave impacting. However, the excessive water overtopping would be a potential threat for the vegetation behind the breakwater, as well as for the underground desalinated water in the reclaimed lands.

Lagrangian Kinematic Criterion for the Breaking of Shoaling Waves

Abstract: An experimental study was conducted with the aim of validating the Lagrangian kinematic criterion (LKC) for the case of breaking of shoaling waves. Monochromatic wave trains were generated in a large wave flume and allowed to shoal and break naturally on an artificial inclination changeable shore, thus allowing inspection of a range of slopes. Instantaneous horizontal Lagrangian water surface velocity was measured by particle tracking velocimetry and compared to the instantaneous propagation speed of the crest on a verge of breaking, the latter calculated using time series produced by resistance-type wave gauges staged along the flume. The inception of a breaker was found to occur when the monotonically increasing horizontal water velocity on the crest, during the process of steepening, approached that of the slowing steep crest, thus confirming the LKC for shoaling conditions. In addition, an objective method of breaking detection was developed utilizing the phase–time method and wavelet analysis...