This model calculates the aerodynamic forces due to aileron deflection. All parameters, including the ailerons specific parameters, are propagated to this model from the AircraftBase model, and therefore their values should not be changed here but only in the complete aircraft model. Additionally, the variables of the global flight conditions are propagated here from the AircraftBase model inside the flightData record. The mass properties of the ailerons (if the weight estimation method is used) are included in the equations in the WingBody component.

All forces in this model act on the supposed aerodynamic center of the ailerons, which is at quarter chord at half of the aileron span length. The position of the ailerons with respect to the fuselage reference point is solved based on the given y coordinates of the aileron root and tip (yAilRoot and yAilTp) and the main wing geometry. The equations to estimate the aerodynamic center location as well as any other estimated ailerons parameter can be bypassed by entering the known value in the Ailerons group in the Derived Properties parameter tab in the AircraftBase model.

The magnitudes of the aerodynamic forces acting along the body x and z axes due to ailerons deflection are solved by using the lateral control coefficients for yaw moment due to ailerons deflection (CnDeltaAil) and roll moment due to ailerons deflection (ClDeltaAil), respectively. The derivation of the normalized lateral control coefficients CnDeltaAil and ClDeltaAil, and their conversions into forces by multiplying them by correct factors are performed according to the method presented by Nelson [1]. The empirical factor kCnDeltaAil (K_C,n,δa) used for solving CnDeltaAil, is calculated based on a formula presented in section 3.3.4 in Reference [2].

The aerodynamic forces due to ailerons deflection are applied with opposite signs in each side of the main wing as the ailerons are set to always deflect symmetrically but in opposite directions. The signs follow the sign convention of control surface deflections presented in ControlSurfaces.Conventional.

References

[1]  Nelson, R. C. (1998) Flight Stability and Automatic Control. 2nd ed. McGraw-Hill.
      Available at: http://home.eng.iastate.edu/~shermanp/AERE355/lectures/Flight_Stability_and_Automatic_Control_N.pdf.

[2]  Erä-Esko, N. (2022). "Development and Use of System Modeler 6DOF Flight Mechanics Model in Aircraft Conceptual Design."
      Available at: modelica://Aircraft/Resources/Documents/EraeEskoThesis.pdf.