Comparing vlm and cfd maneuver loads calculations for a flying wing configuration

This work presents the results of computational fluid dynamics (CFD) based maneuver loads calculations for a flying wing configuration. Euler solutions of the DLR Tau code are compared to vortex lattice method (VLM) results for maneuver loads in the preliminary design stage. The trim parameters of the quasi-steady maneuver load case, the structural deformation and the flow solution are determined in an iterative process. The focus is on a comprehensive loads analysis including a broad selection of load cases to cover the whole flight envelope. This is necessary to ensure a thorough preliminary design. Integration of this approach in an automated, preliminary design process and application of parametric, aeroelastic modeling allows to perform structural optimization loops to evaluate the difference between VLM and CFD on the structural design in terms of structural net mass. 1 MOTIVATION AND INTRODUCTION The design process for new aircraft configurations is complex, costly, and involves various disciplines like aerodynamics, structure, loads analysis, aeroelasticity, flight mechanics, and weights. The task is to substantiate the selected design, based on physically meaningful simulations and analyses. Modifications are much more costly at a later stage of the design process. Thus, the preliminary design should be as good as possible to avoid “surprises” at a 1 Figure 1: The MULDICON structural layout and mass discretization of the basic flight design mass (BFDM).