I am trying to simulate F/A-18 Hornet on Simulink. So, here is how I have made the model:
- Firstly, the initial flight parameters(Alpha, beta, V(magnitude), rho) are being calculated based on the initial values of the states.
- Then, these parameters, along with initial values of the states, are used for calculating the aerodynamic forces and moments.
- As the Aerodynamic forces and moments are in the Wind Axes, I transformed them from Wind to Body using alpha and beta.
- Then, the gravity force, which is transformed from the NED Frame to Body frame, is added to the transformed aerodynamic force.
- Similarly, the thrust force is added, assuming that thrust is only in the X-direction( Body Frame), and no moment is generated because of it.
- Then, total force and moment are sent into the Body Axes 6-DOF Quaternion Block present in Simulink, which gives me the states for the next iteration and process continues.
Please point any mistakes you find out in the above-mentioned iteration process. Now, for checking if the model is correct or not, I planned to give initial conditions as a trim condition, and if the model is correct, the plane should fly in the stable level flight. The trim point is:
V = 300.92 ft/s
[phi, theta, psi] (in rads) = [0, 0.1745, 0] (pitch is 10 degrees)
[p, q, r] = [0, 0, 0]
alpha = 0.1745;
beta = 0;
On giving these initial conditions, the plane flys at a stable level flight. So, is this process of verifying the model enough? If not, then please outline the process which I can use to check my model. Thanks for the help!
PS: Reference for the Aerodynamic Model of FA-18 Hornet:- A. Chakraborty, P. Seiler, and G. J. Balas, “Susceptibility of f/a-18 flight controllers to the falling-leaf mode: Linear analysis,” Journal of guidance, control, and dynamics, vol. 34, no. 1, pp. 57–72, 2011.