Controllable intensification of turbulent mixing in a dual‐shaft stirred system driven by flexible structures

Turbulent mixing in stirred reactors exhibits strong nonlinear dynamics, making performance prediction and targeted control challenging. A flexible structure is introduced into a dual‐shaft stirring system as a tunable dynamical degree of freedom, and a characterization strategy linking structural deformation to flow‐field evolution is proposed. Fluorescence experiments define a flexibility coefficient F s based on the Cauchy number, dividing the system into rigidity‐dominated, reconfiguration, and over‐deformation regimes. Sustained perturbations and mixing enhancement occur only within 1 < F s < 8. An equivalent flexibility parameter F eq is further proposed, showing strong correlation with mixing energy and enabling a shift from empirical operation to structure‐oriented design. Chaotic attractors reconstructed from torque signals reveal enhanced nonlinear dynamics arising from fluid–structure coupling. The reciprocal of the attractor's fractal dimension exhibits a unified relationship with mixing energy, enabling process sensing, and online monitoring. This approach offers insights into predictive, controllable, and intelligent intensification of turbulent mixing.