Study on the Modulation Characteristics of Internal Solitary Waves for Surface Waves Propagating in Different Backdirection
When the internal solitary wave propagates in the ocean,it will cause the convergence and divergence of the surface water,which will modulate the sea surface waves.In this paper,the Computa-tional Fluid Dynamics(CFD)technology is used to study the numerical simulation of surface wave mod-ulation by internal solitary waves.A two-layer model is established to simulate the modulation process of surface waves with different wavelengths and isolated waves in different amplitudes under the same backpropagation.Based on the two basic characteristics of surface wave wavelength and wave height,it is found that the surface wave height induced by internal solitary wave will modulate the surface wave height.When propagating in the same direction,the surface wave height will decrease near the maxi-mum horizontal velocity,but increase when propagating in the opposite direction.At the same time,the distribution of water convergence divergence(horizontal velocity gradient)caused by internal solitary waves will modulate the wavelength characteristics of surface waves,and the surface wave length will become longer in the area of flow field divergence and shorter in the area of flow field convergence.The intensity of surface wave changes under the action of modulation is related to the amplitude of internal solitary wave and the initial wavelength of surface wave.The increase of the amplitude of the internal solitary wave will strengthen the modulation effect and make the surface wave height and wavelength change more significantly.The modulation effect is weakened by increasing the initial wavelength of surface wave.This study focuses on the analysis of the modulation effect of internal solitary waves on surface waves,and obtains the specific correspondence and variation law of the upper water flow caused by internal solitary waves and the modulated surface waves,which is of great significance for under-standing the hydrodynamic process of the modulation of internal solitary waves to surface waves,and helps to better interpret the process of internal wave imaging.
万方数据
维普
