Novel axial-tangential corrugated inner cylinders in Taylor-Couette reactors: CFD analysis of Taylor vortex modulation, turbulence, and mixing efficiency

• Three novel axially tangential corrugated cylinders with distinct wavelengths were designed to manipulate Taylor-Couette (TC) flow dynamics. • A coefficient of variation index was used to quantitatively characterize the spatial uniformity of flow strain rates. • Reynolds Stress Model (RSM) based CFD quantified the critical role of corrugation wavelength in modulating Taylor vortex evolution, turbulence distribution, and mixing performance. • A generalized correlation derived shows macro-mixing time in TC reactors follows a power-law scaling with the average turbulent energy dissipation rate: t ∝〈ε〉 −0.38 . Three novel corrugated cylinders with three-dimensional (3D) roughness elements, featuring periodic axial-tangential wave structures, were developed for Taylor-Couette (TC) reactors to investigate their regulation on Taylor vortex dynamics. CFD modelling coupled with the Reynolds stress model was employed to analyze hydrodynamics, turbulence characteristics and mixing process in TC reactors equipped with these novel cylinders, alongside a classical smooth cylinder for baseline comparison. Simulation results show the corrugated surfaces significantly affect Taylor vortex dynamic, NZ20 exerts the strongest influence on velocity fields, while NZ80 shows the weakest effect, with its flow field closely resembling that of a smooth cylinder. All novel cylinders generate higher flow strain rates compared to the smooth cylinder (e.g., NZ20 achieves a ∼40 % increase), while improving strain rate uniformity (reducing the coefficient of variance by 10–15 %). NZ20 further outperforms others by exhibiting the highest turbulent kinetic energy dissipation rate (∼60% higher than the smooth cylinder), effectively reducing micro-mixing time. At Reynolds number exceeding 1249, NZ20 and NZ40 display steeper concentration-response curves and achieve 10–25% shorter macro-mixing times than NZ80 and the smooth cylinder. This discrepancy arises from the enhanced axial flow induced by their larger corrugation wavelengths; in contrast, NZ80 and the smooth cylinder show comparable mixing times due to NZ80’s high roughness density mitigating such effects. To facilitate practical applications, an empirical correlation for predicting macro-mixing time in TC reactors with various rotating cylinders has been developed. These findings provide critical insights for optimizing TC reactor performance through purposeful surface modification strategies.