Computational Methods for Aero-Structural Analysis and Optimisation of Aircrafts Based on Reduced-Order Structural Models

Abstract

This paper presents comparisons between RANS-based time-domain aero- structural dynamics (ASD) simulations and selected results from the HIRENASD (High Reynolds Number Aero-Structural Dynamics) wind tunnel experiments. At first the ex- perimental setup and the applied computational ASD (CASD) solver are briefly presented. Changes of lift, pressure distribution and wing bending deflection measured during steady polars at different parameter combinations of Mach number and model loading factor are compared to results from numerical simulations. The influences of different turbulence models on the agreement between measured and computed lift-over-drag polars is as- sessed thereafter. A revision of the structural identification of the numerical model is discussed which reveals a significant influence of the model support on eigenshapes and eigenfrequencies. The unsteady pressure fluctuations and model accelerations which were computed for three separately excited wing modes (both first flap-bending dominated and first torsion dominated modes) are compared to the corresponding experimental results. Thereby the capability of the employed CASD solver to accurately quantify experimen- tally observed relations between harmonic structural motion and transonic aerodynamics is demonstrated. This bodes well for upcoming comparisons of simulations and dynamic HIRENASD experiments.