Numerical computation on the DLR-F6 aircraft configuration using different turbulence models
Publish date: 2004-01-01
Report number: FOI-R--1154--SE
Pages: 39
Written in: English
Abstract
Numerical computations were carried out on the DLR-F6 aircraft model. This report is a summary of the computation. A part of the results included here have been presented (by Peter Eliasson) on the 2nd AIAA CFD Drag Prediction Workshop, for which the aerodynamic forces were computed using the explicit algebraic Reynolds stress formulation coupled with the standard k - ? model (EARSM k - ? _model). These calculations were undertaken for both the DLR-F6 wing-body (WB) and wing-body-nacelle-pylon (WBNP) configurations based on DLR adapted grids. The drag polar was also computed for a ? [-3°, 1,5°]. As compared with experimental data, reasonable predictions were obtained for the pressure distributions, yet the lift coefficient was somewhat over-predicted and the drag was underestimated for negative incidences. To investigate the effect of turbulence modelling, the second part of the work has been dedicated to the computation for the WBNP configuration using different turbulence models. These include the EARSM k - ? model, the Spalart-Allmaras (S-A) model, the SST model, the standard k - ? model and a low- Reynolds-Number (LRN) k - ? model. It is shown that the models have reproduced a similar shock position on the upper wing, but that the S-A model returns an earlier one. In modelling flow regions with separation, various models have shown rather different behaviours. The SST model is in general more detective and responsive to flow separation in adverse pressure gradient boundary layers than other models. The LRN k - ? model, by contrast, tend to reproduce suppressed separation bubbles. The other models possess performance intermediate between the SST model and the LRN model.