Influence of rectangular cylinder array on vortex statistics in atmospheric boundary flow

An atmospheric boundary flow was simulated using large eddy simulation, in which the presence of the rectangular cylinders was implemented via the immersed boundary method. The Rortex-based omega method was employed, which establishes a robust criterion capable of detecting rigid rotation while remaining invariant to arbitrary flow conditions and shear contamination. From the instantaneous flow, vortical structures were identified as individual entities using the connected component labeling method. Physical properties, such as the vortex size, convection speed, acceleration, and the vorticity magnitude, were collected to compute the vortex statistics. The key findings were the frequent occurrence of the long-tailed rare events downstream of the rectangular cylinders by which the statistical distributions were considerably altered due to its geometrical features.