Linearized Unsteady CFD for Gust Loads with TAU

Abstract

For decades panel methods have been used in the industrial context to compute the unsteady aerodynamic model for gust load purposes. Additionally corrections with wind tunnel and/or steady CFD data have been applied to overcome the shortcomings of the panel methods, especially in the transonic regime. With the aim to compute a more realistic unsteady aerodynamic model without corrections, computational fluid dynamics (CFD) should replace the panel methods in the future. Due to the large computational costs of CFD, an important enabler for the direct usage of unsteady CFD in the industrial context is linearized CFD. These codes allow computing harmonic motion and harmonic gusts directly in the frequency domain, preventing expansive unsteady computations in the time domain. See [2] and [3] for the here used TAU code and the included linearized frequency domain (LFD) solver from the German Aerospace Center (DLR). In this research the complete aerodynamic model for the standard gust load process has been computed with TAU-LFD. Tau‐LFD provides frequency dependent aerodynamic data in half‐generalized form, which can be introduced in a straightforward manner into the existing standard gust process.