Aeroelastic Simulations in Aircraft Design and Analysis using different Level CFD Methods

Abstract

Three different levels of unsteady CFD methods are used for transonic aeroelastic computations at DLR. These are - in order of increasing fidelity and computational effort - the Transonic Doublet Lattice Method (TDLM) - a linearised frequency domain unsteady method, the boundary-layer coupled blockstructured Euler (EUVIMB) and Full Potential (VUN3D) codes, and DLR's TAU-code, an unstructured hybrid grid Navier-Stokes code. The latter two ones being nonlinear time-domain methods. After a brief review of these codes, their applications for typical aeroelastic problems is presented: Static aeroelastic simulations for a windtunnel model wing and for a complete aircraft configuration, adopting Navier-Stokes and Full Potential with boundary-layer coupled with finite element models and using different spatial coupling methods. Flutter analysis of different wing models (AMP wing, Blended Wing Body), performed both in frequency and time domain, and adopting the TDLM and Tull-Potential with boundary-layer codes. Nonlinear transonic limit cycle flutter (LCO) and buffet of a supercritical NLR7301 airfoil with 2 dynamic degrees of freedom (pitch and heave) partially with flow separation, adopting the Navier-Stokes and the Full Potential code with boundary layer.