Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle
Effect of porosity on an internal solitary wave propagating over a porous trapezoidal obstacle
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DOI：
10.1016/j.oceaneng.2016.11.067
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发表时间：
2017-01
影响因子：
5
通讯作者：
M. Cheng;C. Hsieh;J. R. Hsu;R. Hwang
中科院分区：
文献类型：
--
作者：
M. Cheng;C. Hsieh;J. R. Hsu;R. Hwang
可渗透的海床可能影响在大陆架和近岸上传播的内孤立波的演化。为了研究多孔介质的影响，对大凹陷ISW在多孔介质梯形障碍物上传播的流场和波形反演进行了数值模拟。采用有限体积笛卡尔网格法求解雷诺平均Navier-Stokes方程，采用ak-ε湍流封闭模型和多孔介质模型相结合。数值结果表明，除了孔隙度小于0.2外，随着障碍物孔隙度的增加，波形反演明显减弱。同时，由于渗流和波孔相互作用引起的生产项的急剧减少，涡量和湍流能量的大小显著降低。最大涡度与孔隙度之间呈现出一个斜驼峰状的关系。对于水平平台上的透射波能量，<0.2 but increases moderately whilenf>在强烈的波浪-障碍物相互作用期间，总能量可能降低asnf 0.2。
A permeable seabed may influence the evolution of an internal solitary wave propagating on a continental shelf and nearshore. In order to study the porous effect, numerical simulations are performed to investigate the flow field and waveform inversion of a large depression ISW propagating over a porous trapezoidal obstacle. A finite volume based Cartesian grid method is adopted to solve the Reynolds averaged Navier-Stokes equations using ak-εmodel for the turbulent closure and porous media model together. Numerical results reveal that waveform inversion weakens significantly, as the porosity of the obstacle increases, except when porositynf<0.2. At the same time, the magnitude of vorticity and turbulent energy decrease remarkably due to acute reduction of the production term induced by percolation and wave-pore interaction. Moreover, a skewed hump shaped relation appears between the maximum vorticity and the porosity. For transmitted wave energy on a horizontal plateau, total energy may decrease asnf<0.2 but increases moderately whilenf>0.2 during a strong wave-obstacle interaction.