A Rapid and Low Noise RANS-to-WMLES Condition in Curvilinear Compressible ZDES Simulations

Abstract

The rapid and low-noise strategy of Deck et al. [7] for the RANS-to-WMLES switch compatible with compressible flow solvers on curvilinear grids is presented. It can be used both as an inflow condition or as an embedded resolved turbulence injection and combines Zonal Detached Eddy Simulation, Dynamic Forcing and Zonal Immersed Boundary Conditions (for roughness elements) approaches. The relaxation length is close to 7 boundary layer thicknesses on coarse grids and the feasibility on a 3-element high-lift airfoil is demonstrated. On a flat plate, no spurious acoustic footprint of the inflow is visible in the wall pressure spectra, of which the low-frequency part is obtained. The intermittent nature of wall turbulence is captured. The hybrid RANS/LES context makes the computational effort affordable for industrial applications, e.g. aeroacoustic studies.