(126b) Comparison of Large-Eddy Simulations with Measurements of Turbulent Transport and Mixing in a Confined Rectangular Jet

Large-eddy simulations (LES) of a passive scalar were performed for a confined rectangular liquid jet (Re = 20,000) and compared with measurements made using simultaneous particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF).

Finite-difference and finite-volume LES codes were used to obtain velocity data, which had already provided very good agreement with PIV experimental data in a previous study. Both finite-difference and finite-volume formulations were used to discretize and solve the filtered scalar transport equations. The effects of numerical schemes, subgrid models, and detailed inlet flow conditions on the LES results were investigated. Model validation was performed by comparing LES data for one-point statistics such as the passive scalar mean and variance, turbulence flux and probability distribution functions, with the data from simultaneous PIV/PLIF measurements.

Two-point spatial correlations of passive scalar fluctuations and cross-correlations of passive scalar fluctuations and velocity fluctuations were derived from the LES data and compared with the correlations obtained from the simultaneous PIV and PLIF experiments. The results indicate that the resolved scales from LES may be used to predict the one- and two-point statistical correlations observed in the experiments.