垂直切变风场中声重波的Burgers-KdV方程研究

THE STUDY OF THE BURGERS-KdV EQUATION OF ACOUSTIC GRAVITY WAVES IN THE VERTICAL SHEAR WIND

本文从可压缩流体的原始动力学方程出发,利用二维约化摄动方法推导出垂直切变风场中考虑曳引效应的二维声重波的Burgers-KdV方程,并对其非线性性态作了一些研究.主要结果:1.声重波在远场处能激发起孤波和多周期波列等非线性波动;2.给出上述非线性波动与大气背景风场、密度等的制约关系;3.进一步推测大气风剪切是E_s形成的可能机制.从本文推导出的方程出发,可进一步研究声重波远场处的相互作用、能量转换、不稳定性和定源等问题.

In this paper, we have derived the Burgers-KdV equation of an AGW in the vertical shear wind from the compressible hydrodynamic equations with towing effect by the reductive perturbation method and investigated its nonlinear properties. The results are follows: 1. an AGW can evolve into solitons, shocks and waves ranks at the far fields, 2. we have given the restrictive relations about above-mentioned nonlinear waves and the wind (or density) of the atmosphere, and 3 we guess further that the shear wind of the atmosphere is perhaps formation mechanism of Es. Starting from this B-KdV equation, we can also investigate interactions, energy transport phenomena, instabilities and the source of AGWs at the far fields.