波浪水槽中Stokes五阶波的数值生成

Simulation of Fifth-order Stokes Waves in the Numerical Wave Flume

在Fluent软件平台下运用边界造波法,通过给定造波边界处流体的五阶速度和波面瞬时升高,实现了在数值波浪水槽中使用流体体积VOF法对Stokes五阶波浪的精确模拟,得到的波浪与传统理论值在时域和频域内均吻合很好.此外,为了更好地确定边界水质点输入参数,对现有的若干种五阶波理论解与流函数解在相同的波浪参数下进行对比,发现波浪参数在Ursell判据所定义的五阶波使用范围内时,理论解在波长、波速、波面瞬时升高等参数上区别甚微,但在接近破碎和椭圆余弦波的波浪条件下,波长和波速有较大的差别.

Using FLUENT,simulation of the fifth-order Stokes waves is achieved in the numerical wave flume by defining the inlet boundary conditions and using VOF solver.Comparison with theoretical wave profiles in both time-and frequency-domain shows that the simulated waves are accurate.In order to better determine the inlet water particle kinematics,the existing several models of fifth-order Stokes waves are compared with the stream function method being the most accurate method.These nonlinear solutions all agree well with each other when the wave conditions fall into the Stokes range specified by the Ursell criteria.However,they differ significantly from each other when waves approach the breaking limit and elliptical cosine wave conditions.