  Hybrid Reynolds-averaged Navier Stokes large eddy simulation (RANS LES)
methods have become popular for simulation of massively separated flows at high
Reynolds numbers due to their reduced computational cost and good accuracy. The
current study aims to examine the performance of LES and hybrid RANS-LES model
for a given grid resolution. For better assessment and contrast of model
performance, both mean and instantaneous flow fields have been investigated.
For studying instantaneous flow, proper orthogonal decomposition has been used.
Current analysis shows that hybrid RANS-LES is capable of achieving similar
accuracy in prediction of both mean and instantaneous flow fields at a very
coarse grid as compared to LES. Focusing mostly on the practical applications
of computation, most of the attention has been given to the prediction of
one-point flow statistics and little consideration has been put to two-point
statistics. Here, two-point statistics has been considered using POD to
investigate unsteady turbulent flow.
