A numerical study of coherent flow structures around a cubic bluff body using large eddy simulation

Turbulent flow past a cubic bluff body confined in a channel is numerically investigated using large eddy simulation, as a turbulent model in a computational fluid dynamics simulation tool: the CFX5.1.7 software. The main objective of the present work is to identify the characteristics of coherent vortical structures produced by the presence of the wall-mounted cubic obstacles, including horseshoe vortex systems with upstream of the obstacle, lateral vortices in the vicinity of the lateral faces of the cube and hairpin vortices in the near-wake region. The results of the computational simulations show reasonable concordance with experimental data, especially for velocity profiles. An interesting result is picked up; the increase in the Reynolds number leads to the decrease in the vortex horseshoe. The thermal effect is also studied. The results show that the heat transfer is affected by the turbulence zone where is located the maximum intensity of turbulence.