Computational Drag and Moment Prediction of the DPW4 Configuration Using the elsA Software

Abstract

This paper gives a detailed description of the computational studies done at ONERA in the context of the 4 th AIAA CFD Drag Prediction Workshop. First, it proposes a grid convergence study and a downwash study. Then, the effects due to Mach and Reynolds numbers variations are quantified. The influence of numerical dissipation is also investigated by using different spatial schemes (centered and upwind). All the multiblock structured grids used in this work have been provided by Boeing to the DPW4 community. All the computations are performed by using the ONERA-elsA solver in RANS mode with the Spalart-Allmaras turbulence model, the solutions are post-processed with the ONERAffd72 far-field drag extraction tool. Concerning drag predictions, a very good agreement has been observed between ONERA-elsA results and the near-field drag coefficients (pressure and friction) computed by other DPW4 participants such as Boeing. Furthermore, the farfield ffd72 software has given to ONERA the singular capability to present the values of the different physical drag components (viscous, wave and lift-induced productions). Concerning the pitching moment, ONERA results are very close to Boeing predictions on the same grids. For a first comparison of pitching moment evaluation, this agreement is quite satisfying. Experimental data for the DPW4 configuration is expected to be available in 2010; it will be used for validation purposes.