Large eddy simulations of the turbulent flows of twin parallel jets

Turbulent jet interactions play a significant role in terms of momentum and heat transfer. For example, in next generation nuclear reactors, high temperature flow mixing in the lower plenum and mixing fluctuations in the coolant may influence power oscillations. Thus, the estimation of the mixing condition needs to be accurate. Recent benchmark experiments using particle image velocimetry (PIV) technique provided high-fidelity experimental data that could be used in comparative studies. In the present study, large eddy simulation (LES) numerical methodology is used on a parallel jet system and validated with benchmark PIV experiments. The results indicate good agreement in terms of the merging point and time averaged velocity profile. Spectral analyses via Welch's power spectral density functions are used to analyze frequency information in turbulence jets. The proper orthogonal decomposition (POD) analysis method is applied using a snapshot method. The POD analysis indicates vortex structures similar to those in the benchmark PIV experiment.