Recurrence Quantity Analysis of the Instantaneous Pressure Fluctuation Signals in the Novel Tank with Multi-Horizontal Submerged Jets

Abstract

The circulating jet tank (CJT) has been an alternative piece of equipment for mixing instead of the bottom-stirring tank, which is widely used in industrial applications. The recurrence plots (RPs) and recurrence quantification analysis (RQA) of pressure fluctuation signals (PFS) in the novel CJT were employed to reflect the chaotic extent of jet mixing. The recurrence rate, determinism and averaged diagonal line length of PFS were evaluated at different Reynolds numbers, radial positions and axial positions. The profiles of recurrence rate, determinism and averaged diagonal line length had similar tendency with the increasing Re, which showed that the determinism of PFS increased and the randomness of the chaotic system became small. With the increase in z/H, the recurrence characteristics of PFS at θ m = π/6 gradually increased, which were smaller than that of other θ m . The results of this study provide a deep understanding of the hydrodynamics in the CJT, and thus lay a foundation for further design optimization.

A GRU-CNN Model for Auditory Attention Detection Using Microstate and Recurrence Quantification Analysis

“…• Entropy (ENTR): This index measures the entropy of the diagonal line lengths and is calculated using Equation 6. It discloses the RP complexity of the system structure [55].…”