Fwind computes the contributions to the external forces along the body-axes in non-steady atmosphere (i.e., forces due to non-constant wind and/or atmospheric turbulence). See the descriptions of Cwind, BLwind, Turb1, and Turb2 for more information about the generation of the wind and turbulence velocities and their time-derivatives. The outputs from Fwind are sent to the block FMsort.
x = [V alpha beta p q r psi theta phi xe ye H]' (states) uwind = [uw vw ww uwdot vwdot wwdot]' (wind + turbulence velo- cities and accelerations) {V : airspeed [m/s] } {alpha: angle of attack [rad] } {beta : sideslip angle [rad] } p : roll rate [rad/s] q : pitch rate [rad/s] r : yaw rate [rad/s] {psi : yaw angle [rad] } {theta: pitch angle [rad] } {phi : roll angle [rad] } {xe : x-coordinate in Earth-fixed reference frame [m] } {ye : y-coordinate '' '' '' '' [m] } {H : altitude above sea-level [m] } uw : wind + turbulence velocity along the XB-axis [m/s] vw : wind + turbulence velocity along the YB-axis [m/s] ww : wind + turbulence velocity along the ZB-axis [m/s] uwdot: d(uw)/dt [m/s^2] vwdot: d(vw)/dt [m/s^2] wwdot: d(ww)/dt [m/s^2]The variables which are not actually needed by Fwind have been displayed between curly braces.
Fwind = [Xw Yw Zw]'. where: Xw, Yw, Zw: forces due to non-steady atmosphere, measured along the aircraft's body-axes [N]
GM1: vector with some important geometrical properties of the 'Beaver' aircraft, and its mass (which is assumed to be constant during the motions of interest). Here, the mass m is extracted from GM1. GM1 can be loaded from file by running the utility DATLOAD. Run MODBUILD first if the datafile does not yet exist.