Numerical study of the reaction of initially distant scalars in a transversely oscillating cylinder wake using OpenFOAM

Abstract

This study investigates the effect of the wake generated by a circular cylinder undergoing transverse oscillations on the second-order reaction kinetics between two distant scalars. The cylinder's motion is characterized by frequency and amplitude, and the effects of different amplitude ratios (0.1, 0.25, 0.5, 0.75, and 1.0) are analyzed at fixed frequency regimes (0.1 and 0.5). To accurately characterize the phenomenon, a newly introduced parameter, RAvg (weighted area average of reaction rates), is used in conjunction with laterally integrated time-averaged reaction rates (R̂). A static cylinder is used as a baseline for comparison, and the study keeps the Reynolds number constant at 250 while fixing the Damkohler (0.01) and Schmidt (10) numbers. The study shows that RAvg increases exponentially with amplitude in the higher frequency regime but decreases linearly in the lower frequency regime. Additionally, R̂ increases monotonically in the streamwise direction for all frequency regimes and amplitude ratios. The results provide insights into the complex interactions between fluid dynamics and reaction kinetics, which have implications in fields such as chemical processes and environmental pollution, and energy production etc. Overall, this study highlights the importance of accurately characterizing these interactions and provides a new parameter for this purpose.