Phononic crystals for suppressing crosstalk in ultrasonic flowmeters

Ultrasonic flowmeters that use transit-time ultrasonic transducers face measurement errors due to 'crosstalk,' whereby the working signal travels through the pipe wall and couplings, interfering with the signal from the fluid. Although various procedures have been proposed to solve the issue of crosstalk, they're limited to low-frequency...

Using salt marshes for coastal protection: Effective but hard to get where needed most

Salt marshes fronting coastal structures, such as seawalls and dikes, may offer important ecosystem-based coastal defence by reducing the wave loading and run-up levels during storms. We question (i) how the long-term salt marsh development in the Dutch Wadden Sea relates to the tidal-flat foreshore bathymetry and (ii) how the wave run-up...

Wave attenuation by flattened vegetation (Scirpus mariqueter)

With the capacity to reduce wave energy and trap sediment, Scirpus mariqueter has become an important native species of annual grass for ecology restoration at the Yangtze Estuary in eastern China. Due to seasonal variances of biophysical characteristics, S. mariqueter usually bends and breaks in winter, resulting in flattened stems that may...

Experimental study on a breaking-enforcing floating breakwater

Floating breakwaters are moored structures that attenuate wave energy through a combination of reflection and dissipation. Studies into floating breakwaters have been generally restricted to optimising the attenuation performance. This study presents a novel floating breakwater type that was developed to have good attenuation performance while...

Wave attenuation by salt marsh vegetation

Salt marshes are a characteristic feature of estuaries and coastal seas. They are found in the upper coastal intertidal zones between land and water, which are regularly flooded by tides and surges. They are covered with salt-tolerant vegetation types, such as herbs and grasses. Sheltering from continuous intense hydrodynamic forcing by waves...

Reduction of Wind and Swell Waves by Mangroves

Coastal populations are particularly vulnerable to the impacts of extreme events such as storms and hurricanes, and these pressures may be exacerbated through the influence of climate change and sea level rise. Coastal ecosystems such as mangrove forests are increasingly being promoted and used as a tool in coastal defence strategies. There...

Uncertainty analysis of Hydraulic Boundary Conditions of the Wadden Sea: Phase 1 of activity 2.3

The goal of the uncertainty analyses within the SBW Wadden Sea project is to find out which accuracy in HBC can be achieved, given the current state of scientific knowledge and technical instruments. Furthermore, we wish to quantify the contribution of the SWAN model and other components to the overall uncertainty in HBC. In order to answer...

Wave attenuation by vegetation

Measurements have been carried out at the Paulinaschor, a salt marsh in the Westerschelde, to obtain information of the effect of vegetation on wave attenuation. The data have been analyzed. It appears that wave height is strongly reduced by the vegetation, especially for low water depths. Further analysis of the data has been done, to achieve...

Sea Wave Attenuation by Salt Marsh Vegetation

The main topic of this dissertation is concerned with potential sea wave attenuation by salt marsh vegetation. The overall structure of the dissertation is divided into a literature review and an experimental paper, which is further divided into an in-situ and ex-situ study. Salt marshes have some protected status within the EU and much study is...

Wave attenuation by using reed for bank protection

A literature survey has been conducted on wave attenuation by vegetation with emphasis on reed which has revealed that the influence of various parameters such as the number of reed stalks per unit horizontal area and the dynamic behaviour of the stalks is not known. The two analytical solutions found in this survey are based on linearized...

Wave Attenuation and Wave Set-Up on a Coastal Reef

This study deals with the breaking of waves on coastal reefs, with special emphasis on energy dissipation (wave height attenuation), wave spectrum modification and the characteristics of wave set-up. It has an engineering perspective; its main objective is to provide the practicing engineer with much needed information on the design conditions...

Wave attenuation in a channel with roughened sides

A semi-empirical study l~as made of the attenuation of water waves in a rectangular channel, the side walls of which had been provided with regularly spaced roughness strips. Such strips were found to be highly effective wave dampers. A dimensionless resistance coefficient could be deduced from the attenuation data; this coefficient was mainly a...