Experimental and Numerical Research on the Viscous Flow Field Induced by a Swing Plate

This study investigated the intricacies of the viscous flow field generated by a swing plate, with an emphasis on delineating vortex shedding and energy dissipation phenomena, employing particle image velocimetry (PIV) and large eddy simulation (LES). A resource-efficient, custom-built PIV system was harnessed for experimental data acquisition. The results unveiled a notable congruence between PIV and LES regarding vorticity and vortex localization during abbreviated rolling periods, thereby substantiating the credibility of LES. Conversely, for prolonged periods, LES manifested discrepancies attributed to its constraints in accurately representing elaborate turbulent structures. The investigation was extended to study the influence of varying rolling periods(4-8 s) on the vorticity field. A diminished rolling period culminated in a heightened peak rolling moment and augmented vorticity while preserving the structural integrity of the vortices, indicative of a linear energy transference schema. Furthermore, vortex shedding frequency was found to be directly proportional to the rolling period, with the shedding frequency being half the roll frequency, exhibiting regimented behavior corroborated by a stable Strouhal number. Additionally, an analysis at swing plate heights of 10-50 mm revealed that elevating the swing plate height amplified the vortex intensity up to a threshold, beyond which shear forces instigated vortex fragmentation. These revelations hold paramount significance in the optimization of design and operational strategies across domains including fluid manipulation, energy extraction, and biomimetic propulsion systems.