水平与竖直布置方式下静态混合器内瞬态压力波动混沌特征

为了获得不同布置方式下SK型静态混合器内流体瞬态流动的非线性特征，在湍流状态下(Re=1756～3512)采用高速数据采集器Dewe-3021和压力传感器测量了不同雷诺数和截面处瞬态压力波动时间序列（PFS）；利用混沌吸引子周界测度、混沌动力结构突变以及递归率等参数定量表征水平放置与竖直放置时SK型静态混合器内压力波动特征。研究表明：不同布置状态下静态混合器内PFS的混沌吸引子二维面积增长率随轴向位置的变化趋势基本一致，且S_A-A₀呈线性分布；与水平放置的SK型静态混合器相比，竖直放置时压力波动混沌特性强，混沌动力结构突变小，吸引子演化稳定；混沌形态特征参数能有效区别SK型静态混合器在不同布置状态下的流体动力学特征。

Chaotic characteristics of instantaneous pressure fluctuations in vertical and horizontal Kenics static mixers

In order to determine the nonlinear characteristics of transient flow in a Kenics static mixer (KSM) in different directions under turbulent conditions, high-speed data acquisition equipment (Dewe-3021) and a pressure transducer were employed to measure the time series of instantaneous pressure fluctuation signals (PFS) for different Reynolds numbers and different cross sections. The pressure fluctuations in both horizontal and vertical KSMs were characterized quantitatively through chaotic attractor perimeter measurements, dynamic structure changes and recurrence rate measurements. The pressure fluctuation experiment results show that the growth ratios of the chaotic attractors of the two-dimensional areas of KSM in different orientations have the same variation trend with changes in axial position and both S_A-A₀ plots have linear distributions. The pressure fluctuation in a vertical KSM has stronger chaotic characteristics, smaller dynamic structure change and more stable attractor evolution than for a horizontal KSM. Chaotic characteristics can distinguish the fluid dynamics properties in KSM placed in different directions and give a theoretical basis for promoting widespread industrial applications of KSM.