Surface characters of internal waves generated by Rankine ovoid  

作　　者：Zhaoting Xu Xu Chen Izolda V. Sturova 

机构地区：[1]Instituie of Physical Oceanography and Physical Oceanography Laboratory, Ocean University of China,Qingdao 266003, China [2]Lafrentyev Institute of Hydrodynamics,Russian Academy of Science,Novosibirsk, 630090, Russia

出　　处：《Acta Mechanica Sinica》2006年第5期417-423,共7页力学学报（英文版）

基　　金：The project supported by the National Natural Science Foundation of China (40576010). The English text was polished by Keren Wang

摘　　要：A linear theory on the internal waves generated in the stratified fluid with a pycnocline is presented in this paper. The internal wave fields such as the velocity fields in the stratified fluid and velocity gradient fields at the free surface are also investigated by means of the theoretical and numerical method. From the numerical results, it is shown that the internal wave generated by horizontally moving Rankine ovoid is a sort of trapped wave which propagates in a wave guide, and its waveform is a kind of Mach front-type internal wave in the pycnocline. Influence of the internal wave on the flow fields at the free surface is represented by the velocity gradient fields resulted from the internal waves generated by motion of the Rankine ovoid. At the same time, it is also shown that under the hypothesis of inviscid fluid, the synchronism between the surface velocity gradient fields at the free surface and the internal wave fields in the fluid is retained. This theory opens a possibility to study further the modulated spectrum of the Bragg waves at the free surface.A linear theory on the internal waves generated in the stratified fluid with a pycnocline is presented in this paper. The internal wave fields such as the velocity fields in the stratified fluid and velocity gradient fields at the free surface are also investigated by means of the theoretical and numerical method. From the numerical results, it is shown that the internal wave generated by horizontally moving Rankine ovoid is a sort of trapped wave which propagates in a wave guide, and its waveform is a kind of Mach front-type internal wave in the pycnocline. Influence of the internal wave on the flow fields at the free surface is represented by the velocity gradient fields resulted from the internal waves generated by motion of the Rankine ovoid. At the same time, it is also shown that under the hypothesis of inviscid fluid, the synchronism between the surface velocity gradient fields at the free surface and the internal wave fields in the fluid is retained. This theory opens a possibility to study further the modulated spectrum of the Bragg waves at the free surface.

关 键 词：Internal wave Rankine ovoid Strtified flow Pycnocline 

分 类 号：O35[理学—流体力学]