Development of Deformed CAD Geometries of NASA's Common Research Model for the Sixth AIAA CFD Drag Prediction Workshop

Abstract

A method for modifying the shape of digital geometry representations used in Computer Aided Design (CAD) applications according to experimental pointwise deflection data is described. In the pilot study presented here the method is applied to the CAD geometry of an aircraft wing which is deformed using measured deflections obtained from the associated wing model during a wind tunnel test. The method provides various advantages in Computational Fluid Dynamics (CFD) and other applications. Numerical grids generated on the deformed geometry yield an improved correlation of CFD results to wind tunnel data without the need for aeroelastic computations, which require coupling to a structural model. Additionally, the method is beneficial in aerodynamic optimization, where the optimized shape is usually given in the form of a CFD surface mesh or nodal deflections, which, for further processing or manufacturing purposes, need to be transferred into a CAD geometry description. The paper presents an application to NASA's Common Research Model (CRM) transport aircraft configuration, where deformation measurements from a test campaign in the European Transonic Wind Tunnel (ETW) are processed to provide deformed CAD geometries for use in the forthcoming 6th AIAA CFD Drag Prediction Workshop (DPW-6).