圆柱绕流N一S方程数值解的非线性特性分析

数值模拟并分析了二维圆柱绕流向混沌转捩的情形．通过时间延迟技术和维数嵌入方法对速度时间序列重构相空间，并利用蛎线性动力系统理论方法（诸如相空分析、频谱分析、Ｐｏｉｎｃａｒｅ映射），以及通过对混沌计量（如关联维数、Ｋｏｌｍｏｇｒｏｖ熵、Ｌｙａｐｕｎｏｖ指数等）的计算，对不同雷诺数的Ｎ－Ｓ方程解的特征作了分辨．结果表明，在一定的雷诺数范围内解的是周期或周期的，并且有一个复杂的公叉途径向混沌转捩．

Nonlinear characteristics analysis of the unmerical solutions of Navier-Stokes equation of the flow past a circular cylinder

t A numerical simulation and study of the transition to chaos of the flow past a two-dimensional circular cylinder is presented.Using tools from dynamical system theory,such as phase space diagrans,Frequency analysis,Poincare seetions and the calculation of statistical quantities of chaos:thge correlation dimension,Kolmogorov entropy,Laypunov exponent and so on,the different solutions of Navier-Stokes equation at different values of Reynolds unmber have been identifled and characterized through rreconstructing the phase space of velocity time series by means of time delay and dimension cmbeding.It signifles that the solutions are periodic orr approximatelv periodic in some speeifled range of Reynolds unmber and that a very cimpplex transition occurs with bifureation route to chaos.