aerogrp.hlp

MATLAB在飞行动力学和控制中应用的工具

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System BEAVER - subsystem 'Aerodynamics Group (Beaver)'
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The subsystem 'Aerodynamics Group (Beaver)' contains some blocks
which determine the aerodynamic forces and moments for the 'Bea-
ver' aircraft. The block Dimless first makes the components of
the rotational speed, p, q, and r, dimensionless. The dimension-
less force and moment coefficients are then calculated in the
block Aeromod (Beaver), which contains the actual (aircraft-
dependent) aerodynamic model, and finally, the real values of
these forces and moments are determined by the block FMdims.

The internal structure of the subsystem 'Aerodynamics Group' as
outlined above is valid only for the De Havilland DHC-2 'Beaver',
using the aerodynamic model from ref.[1]. The internal structure
of similar models for other aircraft may look entirely different.
For instance, here, the block Dimless is needed, because the
dimensionless rotational velocities are used as helpvariables for
the actual aerodynamic model in Aeromod, whereas aerodynamic mo-
dels for other aircraft may need different helpvariables.

For this reason, the internal structure of the subsystem 'Aerody-
namics Group' will always depend upon the aircraft model consi-
dered.

Inputs:
=======
  x    = [V alpha beta p q r psi theta phi xe ye H]'     (states)
  uaero= [deltae deltaa deltar deltaf]' (aerodyn. control-inputs)
  yad1 = [a M qdyn]'                   (basic airdata variables,
                                            coming from AIRDATA1)

where:

  V     : true 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, relative to Earth-axes [m]              }
 {ye    : Y-coordinate, relative to Earth-axes [m]              }
 {H     : altitude above sea level [m]                          }

  deltae: deflection of elevator [rad]
  deltaa: deflection of ailerons [rad]
  deltar: deflection of rudder [rad]
  deltaf: deflection of flaps [rad]

 {a     : speed of sound [m/s]                                  }
 {M     : Mach number [-]                                       }
  qdyn  : dynamic pressure [N/m^2]

The variables which are not used by any of the masked subsystems
Dimless, Aeromod, and FMdims, are displayed between accolades.

Outputs:
========
  ydl   = [pb/2V qc/V rb/2V]'              (outputs from Dimless)
  Caero = [CXa CYa CZa Cla Cma Cna]'       (outputs from Aeromod)
  FMaero= [Xa Ya Za La Ma Na]'              (outputs from FMdims)

where:

  CXa, CYa, CZa: dimensionless aerodynamic force coefficients
  Cla, Cma, Cna: dimensionless aerodynamic moment coefficients
  Xa, Ya, Za   : aerodynamic forces [N]
  La, Ma, Na   : aerodynamic moments [Nm]

References.
===========
[1]  R.T.H. Tjee and J.A. Mulder. Stability and Control Deriva-
     tives of the De Havilland DHC-2 "Beaver" aircraft. Report
     LR-556, Delft University of Technology, 1988.

More info.
==========
See the helpfiles DIMLESS.HLP, AEROMOD.HLP, and FMDIMS.HLP for
more info about the masked subsystem blocks within the subsystem
'Aerodynamics Group (Beaver)'. See also AIRDATA1.HLP for details
about the determination of yad1.

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The FDC toolbox, Copyright Marc Rauw 1994-1998.