NUMERICAL STUDIES OF INTERNAL SOLITARY WAVE GENERATIONAND EVOLUTION BY GRAVITY COLLAPSE  

作　　者：LIN Zhen-hua SONG Jin-bao 

机构地区：[1]Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China [2]Key Laboratory of Ocean Circulation and Waves, Chinese Academy of Sciences, Qingdao 266071, China,

出　　处：《Journal of Hydrodynamics》2012年第4期541-553,共13页水动力学研究与进展B辑（英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 61072145, 41176016);the Fundfor Creative Research Groups by National Natural Science Foundation of China (Grant No. 41121064);the State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences (Grant No. LTO1104)

摘　　要：In this study, an analysis on the internal wave generation via the gravity collapse mechanism is carried out based on the theoretical formulation and the numerical simulation. With the linear theoretical model, a rectangle shape wave is generated and propagates back and forth in the domain, while a two-dimensional non-hydrostatic numerical model could reproduce all the observed phenomena in the laboratory experiments conducted by Chen et al. （2007）, and the related process realistically. The model results further provide more quantitative information in the whole domain, thus allowing an in depth understanding of the corresponding internal solitary wave generation and propagation. It is shown that the initial type of the internal wave is determined by the relative height between the perturbation and the environmental density interface, while the final wave type is related to the relative height of the upper and lower layers of the environmental fluid. The shape of the internal wave generated is consistent with that predicted by the KdV and EKdV theories if its amplitude is small, as the amplitude becomes larger, the performance of the EKdV becomes better after the wave adjusts itself to the ambient stratification and reaches an equilibrium state between the nonlinear and dispersion effects. The evolution of the mechanical energy is also analyzed.In this study, an analysis on the internal wave generation via the gravity collapse mechanism is carried out based on the theoretical formulation and the numerical simulation. With the linear theoretical model, a rectangle shape wave is generated and propagates back and forth in the domain, while a two-dimensional non-hydrostatic numerical model could reproduce all the observed phenomena in the laboratory experiments conducted by Chen et al. （2007）, and the related process realistically. The model results further provide more quantitative information in the whole domain, thus allowing an in depth understanding of the corresponding internal solitary wave generation and propagation. It is shown that the initial type of the internal wave is determined by the relative height between the perturbation and the environmental density interface, while the final wave type is related to the relative height of the upper and lower layers of the environmental fluid. The shape of the internal wave generated is consistent with that predicted by the KdV and EKdV theories if its amplitude is small, as the amplitude becomes larger, the performance of the EKdV becomes better after the wave adjusts itself to the ambient stratification and reaches an equilibrium state between the nonlinear and dispersion effects. The evolution of the mechanical energy is also analyzed.

关 键 词：gravity collapse intemal wave energy analysis 

分 类 号：P435[天文地球—大气科学及气象学] TP301.6[自动化与计算机技术—计算机系统结构]