Comparison Study of RANS CFD Simulations for Subsonic Civil Aircraft Configurations

In this paper, the numerical prediction capability of the force predictions in the current computing environments, applicability of turbulence model, and future need of the development are discussed using computational results for geometries used in the series of the AIAA CFD workshop. Computations are conducted for two aircraft wing-body configurations at each cruise Mach condition and a simplified high-lift wing-body configuration with deployed high-lift devices of flap and slat at landing condition using both a multi-block structured grid solver, UPACS, and an unstructured grid solver, TAS-code, which are widely used in Aviation Program Group of Japan Aerospace Exploration Agency. It is shown that to improve eddy-viscosity model or apply more complex model like Reynolds-Stress-Transport models is required for reliable prediction of aerodynamic forces with corner flow separation, which can cause a problem on the consistent prediction of flow fields, and the application of the non-linear stress model could predict the corner flow separation reasonably. For the computations of high-lift configurations, it is shown that although computational results with 30 million grid points show engineeringly reasonable solutions, further increase of grid resolution and high geometric fidelity will be still important to increase the reliability of computational results with improving the fidelity of physical modeling.