Wave-current Interaction In Shallow Water And Its Influence On The Load Of Small-scale Vertical Cylinder

In the coastal region,all kinds of current that cased by the tide and wind or other reason are often observed.The interaction between waves and currents are very common in estuary and bay area.Wave transformation will happen because of the background current,meanwhile,the wave parameters and velocity field will also be changed.Therefore,it is very important to study the wave-current interaction.In this paper,the periodic waves propagation on a uniform current,the periodic waves propagation on a linear shear current,the solitary waves propagation on a linear shear current are simulated in time domain.GN wave theory is used to calculate the wave profile,the horizontal velocity along water depth under the wave crest.The spatial derivatives are discretized through a five-point difference scheme.Morison equation is used to calculate the load of small-scale vertical cylinder.By comparing with the results of other wave theories,we find that when calculate the wave profile,the velocity distribution,the wave force of the wave-current interaction,such as the periodic waves with a uniform current/ linear shear current,the solitary wave with a linear shear current and so on.GN wave theory can always gives the accurate results.As for the vorticity in wave-current domain,when water waves propagating over a uniform current,the vorticity is constant,and will always be zero.When water waves propagating over a linear shear current,the vorticity is constant.When water waves propagating over a nonlinear shear current,the vorticity is will become nonlinear.