Study of Transonic Flutter and Shock Buffet on Benchmark Supercritical Wing

Transonic flutter and shock buffet are complex phenomena involving shock-wave/boundary-layer interaction, a topic that is receiving a lot of attention recently due to the difficulty of modelling these phenomena using industrial computational fluid dynamics tools (cf. the latest instalment of the Drag/Aeroelastic Prediction Workshops). Results produced for the Benchmark Supercritical Wing with a reference flow state of Mach 0.8 in R-134a refrigerant over a range of dynamic pressures and angles of attack are discussed. The computational fluid dynamics code used is DLR-TAU exploiting its extensions towards fluid-structure interaction, efficient linearised frequency-domain incarnation and aeroelastic global stability tools. First, we focus on the static aeroelastic deformation subject to mesh refinement and choice of turbulence model discretisation. Second, we look into the unsteady oscillatory aerodynamics through generalised aerodynamic force matrices and their use for the prediction of flutter boundaries. Finally, we present the underlying shock-buffet instability mode near the onset conditions. A key aspect herein is code-to-code and method-to-method comparisons and assessing when simulations using linear harmonic tools reach their limits.