Research On The Performance Of Foam For The Absorption Of Long Waves In The Laboratory

With the development and utilization of marine environment and coastal resource,the research focusing on waves has become more and more in-depth,and the physical model experiments of waves have become an important approach to studying the performance of waves in different environments.The wave experiments in a laboratory wave sink always focus on the performance of a long period wave.However,because the long wave wave has a faster wave speed and a larger wave length causing that the wave has a larger reflection coefficient and transmission coefficient in the existing laboratory wave absorption,and the energy dissipation is smaller in the wave dissipation device.The result of wave is very poor,which will have a great influence on the final result of the physical model experiment of the wave.It seriously affects the precision of the laboratory tank,and it often takes longer time for the wave experiment,so the experiment period is prolonged.Therefore,it has great practical significance and value to study the effect of wave elimination on the long period wave in the laboratory water sink and the selection of new materials for wave elimination.In this paper,a new type of slope laboratory wave elimination device consisting of soft polyurethane sponge is proposed.The reflection coefficient,transmission coefficient and energy dissipation coefficient of the device are studied at different period and wave height.According to the result of experiment,the wave dissipation property of the sponge material has little influence on the periodic variation,and it can also achieve good wave attenuation effect in the long period wave experiment in the laboratory compared with traditional material.In addition,the factors affecting the wave elimination ability of the device are also studied in this paper in terms of the porosity,the number of sponge layers and the distance between the sponge layers.The experimental results show that when the device is a single layer structure and the distance of the sponge layer is 12 cm,the reflection coefficient and transmission coefficient of the wave dissipation device are low as well as when the porosity varies from large to small,the dissipative effect is relatively obvious.Furthermore,the effect of sponge material on wave energy dissipation is better so the waiting time of the model experiment is obviously reduced,especially for the long period wave.The waiting time can be controlled in 4min,which is helpful to shorten the experimental period.Finally,the Flow-3D software is used to simulate and analyze the structure of soft polyurethane foam elimination.According to the experimental data obtained from the physical model experiment,the parameters of the polyurethane sponge in the numerical simulation are calculated,and the effect of the wave dissipation of the new structure is verified.After analysis the data,the numerical simulation results and data of the physical model are well fitted.On this basis,the effects of various parameters of sponge materials on the wave effect are further investigated by numerical simulation in order to obtain the optimal wave structure.