Wave flume

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

Experimental study on bottom topography change in harbor due to tsunami

Abstract: Bottom topography change due to tsunami was experimentally investigated using a rectangular harbor model in a 2-D wave flume. Water surface level and velocity field were obtained as well to discuss the external forces. Accumulation region was observed in the middle of the harbor inside. Formed was conical bed topography. Erosion was around the accumulated region and at the breakwater head as local scour. These topography changes were caused by the tsunami-induced vortices inside the harbor and at the breakwater head.

Modelling wave-tide interactions at a wave farm

Abstract: The Wave Hub project will create the world’s largest wave farm off the coast of Cornwall, Southwest England. This study is to investigate wave and tide interactions, in particular their effects on bottom friction and sediment transport at the wave-farm coast. This is an ambitious project research which includes the use of a very complex numerical modelling system. The main question to answer is how waves, tidal currents and winds affect the bottom friction at the Wave Hub site and the near-shore zone, as well as their impact on the sediment transport. Results show that tidal elevation and tidal currents have a significant effect on the wave height predictions, tidal forcing and wind waves have a significant effect on the bed shear-stress, relevant to sediment transport, waves via radiation stresses have an important effect on the long-shore and cross-shore velocity components, particularly during the spring tides, waves can impact on bottom boundary layer and the mixing in the water column. Interactions between waves and tides at the Wave Hub site is important when modelling coastal morphology influenced by wave energy devices, this open-source modelling system tool will help the study of physical impacts on the Wave Hub farm area.

Application of photogrammetry for spatial free surface elevation and velocity measurement in wave flumes

Abstract: This article presents a method for obtaining the spatial free surface elevation and velocity field for the water surface in a wave flume over a relatively large measurement area for this type of application (approximately 1.5 m × 1.5 m). The technique employs proprietary videogrammetry software to post-process stereo images captured by multiple synchronised machine vision cameras. Dimensional resolution and other limitations are similar to that experienced for particle imaging velocimetry systems (x, y resolution of 2 mm). Imaging of the free surface was enabled by the use of millions of bespoke slightly positively buoyant fluorescent flakes. Ultraviolet light was used as the primary light source to excite the fluorescent flakes. Reflected ultraviolet light was attenuated by a high-pass filter fitted to the cameras so that only the emitted light from the fluorescent flakes was visible. The software was validated using a simple linear translation experiment. An application is demonstrated for the radiated wave field generated from a submerged sinusoidal heaving sphere for two cases: one single and five consecutive oscillations. Results agree with linear wave theory which indicates that the floating flakes had minimal impact on the water surface particle motion at the scale tested. It is, therefore, concluded that spatial measurement of the free surface elevation and velocity using the method presented has good resolution over a large measurement field. The flakes were found to follow the free surface well, but the measurement area is constrained to where the pattern of flakes exists in the image. Hence, application of floating markers is not suitable for experiments with significant outflow/upwelling which would wash away the floating markers from the intended measurement area.

Influence of wave action on the partitioning and transport of unattached and floc-associated bacteria in fresh water.

Abstract: The dynamic interaction of bacteria within bed sediment and suspended sediment (i.e., floc) in a wave-dominated beach environment was assessed using a laboratory wave flume. The influence of shear stress (wave energy) on bacterial concentrations and on the partitioning and transport of unattached and floc-associated bacteria was investigated. The study showed that increasing wave energy (0.60 and 5.35 N/s) resulted in a 0.5 to 1.5 log increase in unattached cells of the test bacterium Pseudomonas sp. strain CTO7::gfp-2 in the water column. There was a positive correlation between the bacterial concentrations in water and the total suspended solids, with the latter increasing from values of near 0 to up to 200 mg/L over the same wave energy increase. The median equivalent spherical diameter of flocs in suspension also increased by an order of magnitude in all experimental trials. Under both low (0.60 N/s) and high (5.35 N/s) energy regime, bacteria were shown to preferentially associate with flocs upon ces...