Structure evolution of the steady and symmetric vortex pattern around a slender
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摘要: 应用数值计算的方法模拟了细长体截面绕流结构的演变过程.指出随着细长体背涡的发展,导致截面流场的拓扑结构发生变化,会出现一种临界流动状态.并用微分方程的定性理论分析了此时流场中出现的一种高阶奇点.这种高阶奇点的指数为-3/2,它是结构不稳定的,稍有扰动就会产生分叉,使流场的拓扑结构发生变化.得出了定常对称背涡流态下细长体的空间绕流结构图.Abstract: The structure evolution of flow pattern around a slender was calculated by numerical method. It was pointed that the development of slender vortices leads to the change of topological structure about cross flow, and a critical flow pattern will appear. A high-order singular point in this flowfield was analysed by differential equation qualitative theory. The index of the high-order singular is -3/2. The topological structure of this singular point is instable, so bifurcation will be occurred and the topological structure of flowfield will be changed by little disturbance. The 3-dimensional flow structure of the steady and symmetric vortices pattern around a slender was gained.
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Key words:
- slender /
- topology /
- high-order singular point /
- bifurcation /
- structure stability
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