Application of Reynolds stress models to high-lift aerodynamics applications

A recently proposed explicit algebraic Reynolds stress model (EARSM) based on a nonlinear pressure strain rate model has been implemented in an industrial CFD code for unstructured grids. The new EARSM was then used to compute the flow around typical three element high-lift devices used on transport aircraft both in 2D and 3D. For 2D mean flow, various angles of attack have been investigated. Two different grids have been used, one coarse grid with 35,000 nodes and fine grid with 340,000 nodes. Furthermore, a 3D take-off configuration including fuselage was computed using a computational grid with about three million grid points. For the 2D case and pre-stall angles of attack, the new EARSM makes fair predictions. For higher angles of attack, the new EARSM and the baseline EARSM show a large sensitivity to the transition point location. The original transition setting leads to a premature stall while an alternative transition setting gives predictions that are in good agreement with experiments. For lower angles of attack, there are indications on minor improvements. One angle of attack close to the maximum lift was computed for the 3D case and compared with previous computations. No significant differences were found with the new EARSM compared with the baseline EARSM. Also the convergence rate and computational effort by using the new EARSM are comparable with the baseline EARSM.