Koshel Konstantin V, Ryzhov Eugene A
Pacific Oceanological Institute, FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia.
Chaos. 2016 Aug;26(8):083111. doi: 10.1063/1.4961123.
The dynamics of two point vortices embedded in an oscillatory external flow consisted of shear and rotational components is addressed. The region associated with steady-state elliptic points of the vortex motion is established to experience local parametric instability. The instability forces the point vortices with initial positions corresponding to the steady-state elliptic points to move in spiral-like divergent trajectories. This divergent motion continues until the nonlinear effects suppress their motion near the region associated with the steady-state separatrices. The local parametric instability is then demonstrated not to contribute considerably to enhancing the size of the chaotic motion regions. Instead, the size of the chaotic motion region mostly depends on overlaps of the nonlinear resonances emerging in the perturbed system.
研究了嵌入由剪切和旋转分量组成的振荡外流中的两个点涡的动力学。与涡旋运动的稳态椭圆点相关的区域被确定为经历局部参数不稳定性。这种不稳定性迫使初始位置对应于稳态椭圆点的点涡以螺旋状发散轨迹移动。这种发散运动一直持续到非线性效应抑制它们在与稳态分离线相关区域附近的运动。然后证明局部参数不稳定性对扩大混沌运动区域的贡献不大。相反，混沌运动区域的大小主要取决于受扰系统中出现的非线性共振的重叠情况。
