Comparison of High-Fidelity Turbulence Modelling Approaches for Hybrid CAA Studies of Trailing Edge Noise

Turbulence modelling approaches of different fidelity implemented in a three-dimensional incompressible Navier-Stokes solver are validated against DNS data from the literature for a channel flow characterized by a friction Reynolds number Reτ = 395. Wall-resolved large-eddy simulation (WRLES) and wall-stress modelled LES (WSMLES) are considered to obtain a precursor flow solution for a hybrid CFD-CAA simulation of turbulent boundary layer trailing-edge (TBL-TE) noise. A moderate Reynolds number case of the NACA4412 airfoil at an angle of attack of 5° is chosen for evaluating the applicability of these models. Validation of the flow solution for the airfoil simulations is done against direct numerical simulation (DNS) data from the literature. Based on the nature of the near-field aerodynamic data and spectra of wall-pressure fluctuations at locations near the trailing edge and its comparability with DNS, it is observed that the current WSMLES is more computationally efficient than WRLES. However, further work is required to make the combination of that and tripping by unsteady volume forcing give physically accurate results and render it suitable for precursor CFD simulations in hybrid CFD-CAA studies of turbulent boundary layer trailing edge noise in straight trailing-edge airfoils.