Large eddy simulations of erosion of a stratified layer by a buoyant jet

In this study, the LES (Large Eddy Simulation) numerical methodology is used to validate the PANDA experiment for the nuclear reactor containment safety analysis. Specific attention is given to the analysis of the interaction between a buoyant jet and stratified layer. An understanding of the interaction mechanisms will help to quantify turbulent mass transport of the gas components. Good agreement between the numerical results and the experimental data is observed for temporal velocity, gas concentration and temperature data. FFT (Fast Fourier Transform) analysis is applied to check the numerical grid resolution and POD (Proper Orthogonal Decomposition) is applied to investigate coherent flow structures and turbulent mass transport mechanisms. Horseshoe vortices, which has previously been observed experimentally and numerically for buoyant jets, are observed near the round jet.