Numerical Investigation of Flow Around a Multi-Element Airfoil with Hybrid RANS-LES Approaches Based on SST Model

Abstract

Accurate prediction of the flow around multi-element airfoil is a prerequisite for improving aerodynamic performance, but its complex flow features impose high demands on turbulence modeling. In this work, delayed detached-eddy-simulation (DDES) and zonal detached-eddy-simulation (ZDES) was applied to simulate the flow past a three-element airfoil. To investigate the effects of numerical dissipation of spatial schemes, the third-order MUSCL and the fifth-order interpolation based on modified Roe scheme were implemented. From the comparisons between the calculations and the available experimental result, third-order MUSCL-Roe can provide satisfactory mean velocity profiles, but the excessive dissipation suppresses the velocity fluctuations level and eliminates the small-scale structures; DDES cannot reproduce the separation near the trailing edge of the flap which lead to the discrepancy in mean pressure coefficients, while ZDES result has better tally with the experiment.

Investigation and Improvement of Stall Characteristic of High-Lift Configuration without Slats

“…The CFD computations were performed using an in-house structured code [24] with a cell-central finite volume formulation in this paper. Spatial discretization of the viscous terms is done using a secondorder central differencing scheme, and the convective and pressure terms are discretized with a third-order flux difference splitting method of Roe's scheme.…”

Grid density effect for numerical simulation of civil aircraft in post stall

“…Original ZDES [4] was based on Spalart-Allmaras model, however, the ZDES approach in this study was constructed based on the Menter's two-equation SST model [5], which has been validated in the flow around a multi-element airfoil [6].…”

“…The detailed description of the model constant C DES, the grid scale Δ and delayed function f d can be found in reference [6].…”