Study On The Principle Of Wave-current Interactions Based On Fully Nolinear Wave Tank Model

Marine structures play an essential role in the development and utilization of marine resources,and wave and current are the most important loads encountered by marine structures.It is significant to accurately predict the sea conditions that ocean structures may encounter in the design process.Based on the potential wave theory,a completely nonlinear numerical wave tank model is established.Applying the second Green theorem,the problem of the initial boundary value of the simulated wave is transformed into the problem of solving the integral equations,and then the simplest Rankine source Green's function is used to discretize the boundary integral equation.A Mixed Euler-Lagrangian particle tracking method is used to track the position of the fluid particles to capture the instantaneous free surface.The time stepping process is the efficient and stable fourth-order Runge-kutta method to realize the time integral of the free surface condition,and the quadratic function interpolation method is used to re-divide the grid to ensure the numerical stability of the whole calculation process.Using the fully nonlinear numerical wave tank model developed,the real-time simulation of the wave plate motion simulates the finite water depth wave and the shallow water wave respectively.The experimental results,the published results and the shallow water theory are in good agreement with this model,and the wave can be stably propagated for a long time.It is found that the amplitude,frequency of the wave plate and depth are closely related to the nonlinearity of the wave in the finite water depth range.In addition,this paper improves the original numerical wave trough,and establishes a nonlinear numerical wave trough based on the velocity boundary wave method to explore the wave action law under different working conditions.It is found that under the action of the same current,the amplitude is reduced,the wave is flattened,and the wave nonlinearity is weakened;when the reverse flow is applied,the amplitude is increased,the wave is steep,and the nonlinearity of the wave is enhanced.The incident amplitude,velocity,and incident frequency all affect the nonlinearity of the wave.The increase in these parameters will cause nonlinear enhancement of the wave.