An Integrated Model for Lateral Gust Loads Analysis and Dutch Roll Flight Dynamics using a 3D Panel Method

Kurzfassung

An integrated modelling approach for gust and manoeuvre loads analysis is presented. Typically, the unsteady aerodynamics for gust loads are computed by the Doublet Lattice Method. However, this method does not account for effects, which are important from a flight dynamics and manoeuvre loads perspective. E.g., the roll-yaw coupling, also responsible for the flight mechanical eigenmodes like the dutch roll mode, are unaccounted for by the DLM. Since, the dutch roll mode might also be excited by lateral gusts, this might have an influence on the loads response. In this paper, the unsteady aerodynamics are computed by a 3D panel method, capable of capturing the flight dynamics accurately and provide complex Aerodynamics Influence Coefficients for gust loads analysis as a function of reduced frequency similar to the DLM. The aerodynamics of the panel method are validate by comparison with CFD results. Differences in the flight mechanics between the DLM and the panel methods are assessed for a parametric variation of the wing dihedral of an aircraft model. Finally, results from a frequency domain gust loads analysis of a lateral gust for the DLM and the 3D panel method are compared.