Aeroelastic Model Corrections of a Very Light Aircraft

What is it about?

This paper discusses the aeroelastic model corrections employed in the static and dynamic aeroelastic analysis of a very light aircraft. MSC.FlightLoads and MSC.Nastran are used for aeroelastic modeling and analysis. Discussion covers improvement of the aerodynamic solution, aerodynamic modeling approaches and aero-structure coupling alternatives. Aerodynamic calculations are based on the Doublet-Lattice Method (DLM). The aerodynamic solution is improved by including the camber and the angle of incidence of the wing through the addition of initial downwash. DLM-based loads are compared with loads obtained from computational fluid dynamics (CFD) analysis. Additionally, the effect of actuator stiffness is discussed, and different aeroelastic modeling alternatives, such as connecting the wings with a lifting panel, and whether or not to couple the wing-bridging plate with the structural model are compared. The effects of aeroelastic model corrections on static trim, flutter and gust response solutions are investigated.

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Photo by Erika Fletcher on Unsplash

Photo by Erika Fletcher on Unsplash

Why is it important?

In static aeroelasticity, it is shown that the DLM correction considerably influences the pressure distribution and results in a relatively closer distribution to CFD compared to the initial DLM result. Secondly, the dynamic aeroelastic stability of the isolated wing and full aircraft models are analyzed. The significance of control surface actuator stiffness is discussed by presenting the change in flutter outputs with various aileron stiffness values. Lastly, in the dynamic response analysis part, the gust response of the VLA is analyzed for a symmetrical, vertical gust in 1-cosine waveform. It is shown that the aeroelastic coupling of the wing bridging plate leads to greater dynamic responses and gust load factors are found to be more critical than the limit maneuvering load factors for the analyzed VLA.