Proper Orthogonal Decomposition of Flow Structures around a Surface-Mounted Cube Computed with Detached-Eddy Simulation

In this paper the flow passing a cube mounted in a channel is studied via detached-eddy simulation (DES). The results are compared to previous studies, where large eddy simulation (LES) have been used. The mean velocity profile found in this paper was found to match with other references above the cube but not behind the cube. The shear stress was underpredicted by the DES computations on top of the cube. Behind the cube the LES and experimental studies show a much more smeared shear layer than the DES calculation. The proper orthogonal decomposition (POD) modes are calculated and investigated. The first mode, which corresponds to the mean flow, was found to contain the flow structure of the large separation above the cube. The POD modes calculated from the DES results show higher percentage of energy in the first mode than the POD calculated from LES results.