组合KdV方程的双扭结孤立波及其稳定性研究

利用扩展的双曲函数法得到了combined KdV-mKdV (cKdV)方程的几类精确解,其中一类为具有扭结—反扭结状结构的双扭结单孤子解.在不同的极限情况下,该解分别退化为cKdV方程的扭结状或钟状孤波解.理论分析表明,cKdV方程既有传播型孤立波解,也有非传播型孤立波解.文中对双扭结型孤立波解的稳定性进行了数值研究,结果表明,cKdV方程既存在稳定的双扭结型孤立波,也存在不稳定的双扭结型孤立波. 关键词： cKdV方程 双扭结单孤子 稳定性

The single solitary wave with double kinks of the combined KdV equation and its stability

We obtained six classes of exact solutions for the coupled KdV equation by the extended hyperbola function expansion Method.One of the solutions is a solitary wave solution, which has two peaks.This solution is reduced to the kink or bell-like soliton solution of the coupled KdV equation under different limitations. We also investigated the stability of the single solitary wave solution with double peaks numerically.The results indicate that the solution is stable when the amplitude of the disturbance, which has long wave length, and is very small.