Analysis And Modelling Of Unsteady Aerodynamic Based Fly-Wing Configuration At High Incidence

A wind tunnel experiment has been conducted on the traditional Fly-Wing configuration SACCON included pitch force oscillation and roll force oscillation. According to the raw experimental data, a whole set of the dynamic data’s manipulating methods has been introduced and used include the data filtering, truncating data, translating data and the mean of the period data. The result of dynamic forces and moments has been analyzed with the structure of the flow field topology in the different pitch angles, roll angles and frequencies.And then, the Phase-shift method, the continuous Fourier series method, and the discrete harmonic analysis, and the single-point method have been introduced and proved. The “in-phase” and “out-of-phase” aerodynamic derivatives have been calculated via the Harmonic Analysis method. According the aerodynamic derivatives, the comparison of the base harmonic analysis and traditional linear mathematical model with the dynamic data has been proved the traditional model’s limitation, especially in the strong nonlinear and unsteady angle zones.Lastly, an unsteady mathematical representation has built using nonlinear differential equation model, then the two-step linear regression method has been taken for in identification of the model unknown parameters estimation and given the characteristic time constants of pitch and roll with their standard square deviations. There is a good agreement between data predicted by mathematical model and experimental data obtained in the large amplitude forced oscillatory tests, and it has fully been proven that the model’s applicability simulating the unsteady and nonlinear effects of the fly-wing configure aircraft at high incidence. Although thus, there need to be in-deep study about complex configure aircraft.