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.