Recent Progress in Simulation of Transonic Unsteady Aerodynamics and Fluid-Structure Interaction

Abstract

We present a digest of selected activities at DLR focusing on the application and validation of the CFD solver TAU and related fluid-structure coupling techniques for unsteady flow problems related to fixed-wing aircraft in the transonic regime. Special emphasis is put on the simulation of motion-induced unsteady flow due to forced harmonic excitation, which constitutes the key problem in the prediction of the flutter phenomenon. Various configurations ranging from a basic two-dimensional wing/control surface model over a wing-pylon-nacelle model to three-dimensional swept wing models are investigated in the forced motion context. Apart from that, instability-induced unsteadiness due to shock buffet and dynamic response problems due to externally induced unsteady flow are discussed on the basis of a wing-tail configuration. Most of the presented numerical simulation results are validated with wind tunnel measurements, many of which were obtained by DLR itself during the last decade.