Mandatory settings for hybrid RANS/LES computations on the LEISA high-lift 3-element airfoil (Preliminary version)

Test case set-up for hybrid RANS/LES In general, AoA=6 and SST local transition for all 3 elements For partner using SA based DES methods: AoA =6, and SA local transition on slat and wing, full turb. on flap Option: AoA=6, and SST transition for all 3 elements New run 18% retracted chord length and 128 cells in spanwise direction According to the mandatory grid (100c farfield distance, ~200000 points per layer): total number of points ~25Mio Time step Δt=1e-5

Expected results Partners should provide Cd and Cl time history Surface data: Cp, Cf (mean and r.m.s.) Field data: mean values for velocity <ui>, velocity gradients d<ui>/dxj, pressure <p>, eddy viscosity; correlations of velocity fluctuations <ui’uj’> and r.m.s. pressure <p’-<p>>. Here <> denotes averaging in time and spanwise direction Time series of pressure p(.,t) at single probes in the nose region of the main wing element for comparison with KULITE measurement. The positions of the KULITES will be comunicated as soon as they are available DLR will check position of PIV windows in experiments. But data postprocessing is independent of this information

Assessment of resolved and modelled part of turbulent shear stress Consider relative contribution of modelled to resolved shear stress Actual DES modus τxz-modelled τxz-resolved RANS simulation 100% 0% (D)DES simulation 100% in RANS mode 0% in RANS mode ~50% „grey area“ ~50% <10% in LES mode > 90% in LES mode