Numerical Study On Hydrodynamic Characteristics Of Flat-submerged Breakwater Composite Structures

Submersible breakwater,as a nearshore protective structure often used in practical engineering,can play a major role in weakening the waves of the outer sea,so as to achieve the purpose of protecting the beach and coastal structures from being infringed.Compared with other types of breakwater,submerged breakwater is a kind of breakwater located below the water surface,which has great advantages in environmental improvement and water flow.In this paper,a numerical model is established based on OpenFOAM,and the reliability of the model is verified through physical model tests.The interaction between structures and regular waves under different working conditions is simulated,and the wave dissipation and mechanical characteristics of the plate-submerged dam composite structure are discussed.In this thesis,the simulated wave generated by the method using now relatively mature push board wave method,and for the entire numerical flume,can produce the main including wave wave zone,the interaction between waves and structures of experimental area and prevent secondary reflection wave area three paragraphs in the corresponding test position with wave probe monitoring stations,and near the free surface is the secondary encryption,to ensure that in the process of simulation can be more accurate record of the wave and structure and the interaction of waves.The corresponding position of the structure is equipped with pressure measuring points,which are mainly used to detect the pressure of the structure and the total wave force,so that the stress state of the surface of the structure can be seen more intuitively.Through setting the wave elements under different conditions,the influence of the water depth at the top of the embankment,the width of the submerged embankment,and the space between structures on the reflection coefficient,pressure and wave force of the combined structure of the plate-submerged embankment is analyzed.According to the results of numerical calculation,within the scope of this numerical simulation,the relative water depth of the embankment has a significant influence on the wave cancellation effect of the structure,and the wave cancellation effect of the structure will become better and better with the decrease of the relative water depth.There may be a critical value between the relative width B/d=0.8-1.1 of the submerged dike,which can change the wave-dissipation characteristics of the structure.In other cases,with the increase of the width of the structure,the final performance of the wave elimination effect is also better and better.Different structure spacing has a certain influence on the wave dissipation characteristics of the plate-submerged dike-composite structure,which presents different laws under different working conditions.The strong pressure on the tablet-submerged breakwater composite structures with flat-submerged breakwater composite structure relative to the increase of the depth of the water,and the smaller the strong pressure on its surface,the flat-submerged breakwater on the composite structure surface pressure is strong with the increase of relative depth of the structures present gradually decreasing trend,and with the increase of relative plate width,the tablet-submerged breakwater combination structure surface pressure decrease.When R/d=0.03,the pressure of the structure is the largest,then when R/d=0.06,the pressure of the structure is the smallest when R/d=0.10.The relative width and relative spacing of submerged dike have significant influence on the compressive strength of structure.Under 90% working conditions,the larger the relative width of submerged dike,the smaller the compressive strength on the upper surface of structure,that is,the compressive strength on the upper surface of structure decreases with the increase of the relative width of structure.The pressure P of structures with three different spacing of submerged dikes decreases with the increase of X/W in most working conditions.The water depth at the top of the dike has a certain influence on the total wave force of the plate-submerged dike combined structure,and the total positive and negative wave forces on the structure are symmetrically distributed on the abscess.The relative width of submerged dike and the relative distance between submerged dike have different effects on the structure,which show different laws under different working conditions.