Computation and Evaluation of Dynamic Derivatives using CFD

Abstract

This paper focuses on the computation of dynamic derivatives for full aircraft configurations. The flow is modelled using the Euler and RANS equations and an unsteady time-domain solver is used for the computation of aerodynamic loads for forced periodic motions. The study investigates the variation of damping values through the transonic regime and for several permutations of motion parameters for the Standard Dynamics Model geometry. A benchmark against experimental data is presented for the Transonic CRuiser wind tunnel geometry. For the SDM, strake vortices and their breakdown are observed when increasing the mean angle of attack during the applied pitch sinusoidal motion. A good agreement is obtained with available experimental data. For the TCR, a validation of longitudinal aerodynamic characteristics is first considered. Numerical experiments for the estimation of damping derivatives and for large amplitude forced oscillations in pitch axis are compared to wind tunnel data. Simulations are in agreement with experimental data up to high angles of attack.