Numerical simulation and verification of the flow around a surface mounted cubic body placed in a fully developed turbulent channel flow

In the paper detailed investigations of the flow structures around a cubic body in a turbulent channel flow at high Reynolds numbers are carried out by means of a large-eddy-simulation (LES). Special attention is turned to the resolution of secondary structures of the flow field which up to now could not be resolved by numerical calculations. By simplification of the subgrid energy equation and the development of fast Poisson solvers efficient calculation times are reached. Due to the correct approximation of the velocity gradients at the sharp edges of the body the shape and the size of the numerical determined separated flow regions agree very well with corresponding experiments. To resolve the details of the flow in the immediate neighbourhood of the cubic body the implementation of a local mesh refinement procedure in the code was necessary. For this a concept of locally embedded grids was developed. With the code described in the paper the following progress was made: The global flow structures agree very well with corresponding experiments carried out by Martinuzzi(6). The numerical calculation of the streamlines gives an answer on the interaction of different separation zones. With the code secondary flow structures which up to now could not be resolved by numerical calculations are visualized and localized in the flow field. The numerical calculations described in the paper demonstrate the superiority of the large-eddy-simulation (LES) for the prediction of the turbulent kinetic energy especially in comparison with the k-epsilon model.