Prediction of aerodynamic derivatives based on time accurate CFD simulation

摘要

Dynamic derivative of aircraft is one of the key parameters for the designing of aerodynamic characteristics. Accurately obtaining the dynamic derivative does make sense for aircraft performance evaluation and flight control system designing. An in-house flow solver called HUNS3D is used to numerically simulate the unsteady flow over the research subjects with forced oscillation dynamic motions. After the time history of aerodynamic force and moment coefficients is achieved, least squares method is used to extract static and dynamic derivative from the time history. To validate the dynamic derivative results achieved by least squares method, NACA0012 airfoil and Standard Dynamic Model (SDM) are used as two test cases. For NACA0012 airfoil, the present hysteresis loops accord with the experimental data from AGARD Report 702, which makes the foundation for a correct prediction of dynamic derivatives. And the dependency of dynamic derivatives on a number of parameters, such as Mach number, initial angle of attack is assessed.