Numerical Analysis Of Hydrodynamic Characteristics Of Water Plate Under The Action Of Tsunami Wave

Flat plate structure is widely used in coastal and marine engineering,such as breakwater,cross sea bridge and other structures.However,due to the impact of tsunami wave or improper design,the structure is often damaged or even caused great disaster.Therefore,the research on the hydrodynamic characteristics of fixed horizontal plate under the action of tsunami wave is of great significance and reference value for the design of offshore engineering structures.Firstly,the theoretical background and the significance of the previous research are briefly introduced.Then,this thesis introduces the two-dimensional numerical model established by OpenFOAM open source software package,the control equations,boundary conditions and initial conditions used in the numerical model,the wave making and wave elimination in the relaxation zone,and the method of free surface treatment.Then,through the simulation of the physical numerical model experiments presented in the relevant literature,the numerical wave making,the change of free surface,and the structure in OpenFOAM are verified The accuracy of the wave force.On this basis,the related research contents and conclusions are as follows:(1)Based on OpenFOAM model,the hydrodynamic characteristics of a flat plate under solitary waves are systematically simulated by changing the width and relative clearance ratio of the horizontal plate.The effects of the width and relative clearance ratio on the wave force,transmission coefficient and reflection coefficient are discussed and analyzed.The results show that the change of plate width and relative clearance ratio has little influence on horizontal wave force,but has obvious influence on vertical wave force,and the influence becomes more significant with the increase of relative clearance ratio;with the increase of relative clearance ratio,the horizontal extreme wave force decreases gradually,and the vertical extreme wave force increases first and then decreases.With the increase of relative clearance ratio,the reflection coefficient decreases and the transmission coefficient increases;when the relative clearance ratio is constant,the reflection coefficient increases and the transmission coefficient decreases with the increase of plate width.(2)Based on OpenFOAM model,the hydrodynamic characteristics of water plate under N-wave action are systematically studied.The influence of N-wave on the wave forces and the transmission and reflection coefficients of water plate and underwater plate under different plate width,relative amplitude ratio and relative submergence ratio are discussed and analyzed.The results show that with the increase of plate width,the horizontal extreme wave force decreases gradually,and with the increase of relative amplitude ratio,the horizontal extreme wave force increases gradually;the vertical extreme wave force increases gradually with the increase of plate width and relative amplitude ratio.The horizontal and vertical extreme wave forces of underwater plate decrease with the increase of plate width parameter,and increase with the increase of relative wave amplitude ratio.With the increase of the relative amplitude ratio and the plate width,the reflection coefficient of the water plate and the underwater plate increases gradually,while the transmission coefficient decreases on the contrary.(3)Based on OpenFOAM model,the hydrodynamic characteristics of water plate under the action of double solitary waves are systematically studied.The influence of double solitary waves on the wave forces of water plate and underwater plate under different plate width,relative amplitude ratio and relative submergence ratio is discussed and analyzed.The results show that when the flat plate is above the still water surface,the change of the plate width and the relative amplitude ratio has little effect on the horizontal wave force,but more obvious on the vertical wave force,and the effect becomes more obvious with the increase of the clearance height;when the flat plate is below the still water surface,the change of the relative amplitude ratio has little effect on the horizontal wave force and the vertical wave force,With the increase of submergence depth,the influence becomes more obvious.