ˆäã “¹—YiMathworks Japanj Wall-modeled LES applied to the flat-plate turbulent boundary layer In Large-eddy simulation (LES) only the large scales of motion are resolved while the effects of small unresolved eddies are modeled; this enterprise is referred to as subgrid-scale modeling. In LES, this takes the form of closures for the subgrid contributions to the fluxes of momentum, energy and scalar transport insofar as these appear in the LES equations for the resolved scales. LES is now a viable alternative to direct numerical simulation (DNS) and experiment, however, numerical resolution requirements still limit applicability of LES of the wall-bounded turbulent flows at moderate Reynolds number. Instead of resolving the near wall region, we develop a virtual wall model which calculates the local wall-normal velocity gradient, or equivalently, the wall-friction velocity. The wall model provides the boundary conditions for the LES. In this talk, the LES methodology is applied to a flat-plate turbulent boundary-layer (TBL) flow at large Reynolds numbers. First, LES of the zero-pressure gradient TBL are presented. Second, we discuss the LES of a TBL under adverse pressure gradient. Computed statistics are found to be consistent with recent experiments. Finally, time series velocity signals obtained from LES within the logarithmic region of the zero-pressure gradient TBL are used in combination with an empirical, predictive inner-outer wall model to calculate the statistics of the fluctuating stream-wise velocity in the inner region of the zero-pressure gradient TBL, that is not directly accessible to the wall-modelled LES. [1]: Cheng, W., Pullin, D.I. and Samtaney, R., 2015. Large-eddy simulation of separation and reattachment of a flat plate turbulent boundary layer. Journal of Fluid Mechanics, 785, pp.78-108. [2]: Inoue, M., Pullin, D.I., Harun, Z. and Marusic, I., 2013. LES of the adverse-pressure gradient turbulent boundary layer. International Journal of Heat and Fluid Flow, 44, pp.293-300. [3]: Inoue, M., Mathis, R., Marusic, I. and Pullin, D.I., 2012. Inner-layer intensities for the flat-plate turbulent boundary layer combining a predictive wall-model with large-eddy simulations. Physics of Fluids, 24(7), p.075102. [4]: Inoue, M. and Pullin, D.I., 2011. Large-eddy simulation of the zero-pressure-gradient turbulent boundary layer up to Re_theta = O(10^12). Journal of Fluid Mechanics, 686, pp.507-533.