DPW-7: Steady and Unsteady Computations of the Common Research Model at Different Reynolds Numbers

Abstract

This article presents the numerical computations performed at ONERA for the Seventh AIAA Drag Prediction Workshop. By introducing Reynolds numbers up to 30 million closer to the flight conditions, greater lift levels beyond the design point, and time-accurate simulations, this new session has allowed the previous studies to be extended. The Common Research Model aircraft configuration has been considered in its academic wing-body version and calculated in this work with point-matched structured grids. The ONERA Cassiopee software as well as the elsA solver and the FFDπ far-field drag code have been used. The grid convergence study has shown larger pressure drag variations than what was obtained at the cruise lift coefficient, but increasing the Reynolds number seems to reduce this trend. Then, the angle-of-attack sweep study with the lift, drag, and moment polars has given the opportunity to assess different numerical settings such as the Spalart–Allmaras and shear stress transport turbulence models with the quadratic constitutive relation approach (QCR-2000) and to discuss the comparison between computational fluid dynamics results and wind-tunnel data. Concerning the Reynolds number increase, it has appeared that the main part of drag reduction comes from the friction () and viscous pressure drag () components. The prediction of pitching moment increments due to Reynolds number variations still needs to be significantly improved. Finally, for an angle of attack above 4.00 deg, by the use of unsteady Reynolds-averaged Navier–Stokes computations, an unsteady buffet phenomenon has been observed and analyzed.