Subsystem Airdata3
Airdata3 computes the total
temperature
Tt and Reynolds numbers
Re
and
Rc. Actually, the Reynolds numbers are no
'airdata variables', but they are closely related. Also, they are
very important in aerospace engineering, in particular for the evaluation
of windtunnel experiments. The block
Airdata3 is contained in the
subsystem
Airdata Group of the system
Beaver. Other airdata (-related) variables are
computed in the blocks
Atmosph,
Airdata1, and
Airdata2, which also contained in the subsystem
Airdata Group.
Inputvectors: x, yatm, and yad1
x = [V alpha beta p q r psi theta phi xe ye H]' (states)
yatm = [rho ps T mu g]' (atmospheric properties, computed in
the block Atmosph)
yad1 = [a M qdyn]' (airdata variables, computed in Airdata1)
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] }
rho : airdensity [kg/m^3]
{ps : static pressure [N/m^2] }
T : temperature [K]
mu : dynamic viscosity [kg/(m*s)]
{g : acceleration of gravity [m/s^2] }
{a : speed of sound [m/s] }
M : Mach number [-]
{qdyn : dynamic pressure [N/m^2] }
The inputvariables which are not actually used by
Airdata3 have been
displayed between curly braces.
Outputvector: yad3
yad3 = [Tt Re Rc]',
Tt : total temperature [K]
Re : Reynolds number per m [1/m]
Rc : Reynolds number (using the mean aerodynamic chord as
characteristic length) [-]
Parameters to be defined in the Matlab workspace
-
GM1: vector with some important geometrical properties of the
'Beaver' aircraft, and the mass of the aircraft (which is
assumed to be constant during the motions of interest). Here, the mean
aerodynamic chord is needed, in order to find the Reynolds number
Rc. GM1 can be loaded into the workspace from
file by running the utility DATLOAD.
Run MODBUILD first if the datafile
does not yet exist.