Comparative analysis of turbulence structure in near-wall and midplane regions of a high-Reynolds-number lid-driven rectangular cavity

The lid-driven cavity flow is a classical benchmark for validating computational fluid dynamics models and investigating turbulence mechanisms. However, most previous studies have focused on the midplane (x/D = 0.5), while systematic measurements of the near-wall plane (x/D = 0.2), which is directly affected by wall confinement, remain scarce. This limitation hinders a comprehensive understanding of three-dimensional turbulence in confined cavity flows. In this study, particle image velocimetry was adopted to conduct synchronized, high-resolution measurements on both the near-wall plane and midplane of a rectangular cavity over a high Reynolds number range from 1.161 × 105 to 3.483 × 105. The experimental results show that, compared with the midplane, the primary vortex core on the near-wall plane shifts rightward by approximately 40% with a displacement coefficient of 0.71–0.76. Flow statistics indicate that the near-wall plane exhibits a significantly lower mean velocity, and the proportion of low-velocity regions (