## Subsystem Power (Beaver)

Power (Beaver) computes the engine power and non-dimensional pressure increase across the propeller for the DHC-2 'Beaver' aircraft, using the engine power model from ref.[1]. Power is contained in the subsystem Engine Group of the system Beaver. This subsystem also contains the blocks Engmod (Beaver) and FMdims.

### Inputvectors: x, uprop, yatm

      x    = [V alpha beta p q r psi theta phi xe ye H]'     (states)
      uprop= [n pz]'                                  (engine inputs)
      yatm = [rho ps T mu g]'   (atmospheric properties, computed in
                                                   the block Atmosph)

      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]                           }

      n    : engine speed [RPM]
      pz   : manifold pressure ["Hg]

      rho  : air density [kg/m^3]
     {ps   : static pressure [N/m^2]                                }
     {T    : air temperature [K]                                    }
     {mu   : dynamic viscosity [kg/(m*s)]                           }
     {g    : acceleration of gravity [m/s^2]                        }

Variables which are not actually used by Power (Beaver) have been displayed between curly braces.

### Outputvector: ypow

      ypow = [dpt P]'

      dpt  : dimensionless pressure increase across the propeller [-]
      P    : engine power [Nm/s]

### References

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