Abstract: In order to evaluate moment of attractor morphology in a Kenics static mixer (KSM), 360 groups of pressure fluctuation signals (PFS) in vertical upward flow were measured in the turbulent region with a Re range from 1756 to 3512. Reference sections were placed in the chaotic attractor field of pressure fluctuation signals based on the phase-space reconstruction theory. The relationship between chaotic attractor morphology and Re, radial and axial positions was investigated. The secondary flow in the cross-sections consisted of different scale free and forced vortices which formed the Rankine vortex. The slopes of chaotic attractor moment at rm/R≤0.3 and rm/R>0.8 decreased with the increase of Re. The slopes of moment in the bulk zones at 0.4≤rm/R≤0.8 first increased, then decreased, and finally increased with the increase of Re. The chaotic attractor morphology of PFS was sensitive to evaluation of topology structure, which was helpful to understanding the nonlinear dynamic mechanism of vertical upward flow.

Key words: static mixer, pressure fluctuation, chaos, attractor morphology

摘要： 为了探讨湍流状态下(雷诺数Re=1756~3512)旋流静态混合器内混沌拓扑结构演化规律，对采集的360组竖直上升螺旋流瞬态压力波动时间序列进行相空间重构，通过在其混沌吸引子域中放置参考截面，考察旋流静态混合器内瞬态流混沌吸引子形态特征量与雷诺数、轴向位置和径向位置之间的关系. 结果表明，轴截面内径向二次流为不同尺度强制涡和自由涡组合的兰金涡，在rm/R≤0.3和rm/R>0.8(rm为测量点到截面中心距离，R为混合管半径)处混沌吸引子特征量随Re增大而减小，而0.4≤rm/R≤0.8处主体区内压力波动信号混沌吸引子特征量随Re增大呈先增大后减小再变大的趋势. 瞬态压力波动信号混沌吸引子形态特征量对漩涡结构演化敏感，有助于理解竖直上升螺旋流的非线性混沌动力学机制.

关键词: 静态混合器, 压力波动, 混沌, 吸引子形态