Transformation of wave field by permeable vertical wall

Laboratory experimental studies were conducted to study the interaction of gravity waves with models of permeable vertical walls, which are formed by piles of circular cross-section. Experiments were conducted in a wave channel, where waves of different height, period and wavelength were generated. Visual studies using video and photo equipment and instrumental studies using piezoresistive wave height sensors and wave pressure fluctuation sensors were performed. The use of a group of sensors made it possible to determine the spatio-temporal characteristics of the wave field and the features of the transformation of waves during their interaction with continuous and permeable vertical walls. Statistical methods of processing and analyzing experimental data made it possible to obtain integral and spectral characteristics of wave motion both in front of the vertical wall and behind it. It was established that the heights of waves in front of the permeable vertical wall and the heights of reflected waves increase with a decrease in wall permeability and wavelength and an increase in the frequency of the wave field. It was determined that the power spectral densities of wave pressure fluctuations have the highest values immediately in front of the frontal part of the vertical wall, and these levels decrease as the permeability of the wall increases. A particularly significant increase in the levels of pressure fluctuations was observed in the high-frequency region, which is due to the action of high-frequency small-scale pressure sources, which are small-scale components of the wave motion generated during the interaction of the incoming wave with the vertical wall. The results of research showed that a permeable vertical wall with piles of a circular cross section is a sufficiently effective protective structure that significantly reduces the penetration of storm waves into the protected water area, especially in conditions of low permeability, this design also allows improving environmental conditions and significantly saving material resources during construction coastal protection structure.