Predictive capability of Large Eddy Simulation for point-wise and spatial turbulence statistics in a confined rectangular jet

Large Eddy Simulations (LESs) were performed for a confined rectangular liquid jet with a co-flow and compared in detail with particle image velocimetry (PIV) measurements. A finite-volume CFD library, OpenFOAM, was used to discretize and solve the filtered Navier–Stokes equation. The effects of grid resolution, numerical schemes and subgrid models on the LES results were investigated. The second and fourth order schemes gave similar performance, while the fourth order scheme costs much more computationally. Subgrid model comparison showed that the locally dynamic procedure is necessary for complex flow simulation. Model validation was performed by comparing LES data for the point-wise velocity statistics such as the mean and the root-mean-square velocity, shear stress, correlation coefficient, velocity skewness and flatness with the PIV data. In addition, LES data for the two-point spatial correlations of velocity fluctuations that provide structural information were computed and compared with PIV data. Good agreement was observed leading to the conclusion that the LES velocity field accurately captures the important characteristics of all the turbulent length scales present in the flow, from the fully resolved energy-containing eddies to the subgrid-scale dissipative eddies.

► Large Eddy Simulations (LES) were performed, using OpenFOAM, for a liquid jet with a co-flow.
► Results were compared with particle image velocimetry (PIV) measurements.
► The effects of grid resolution, numerical schemes and subgrid models were investigated.
► Good agreement of point-wise and the spatial velocity statistics were observed.
► LES accurately models all the turbulent length scales present in the flow.