Notation

General

a | lift curve slope dC_{L}/dα |

a_{0} |
first term in Fourier expansion of β |

a_{1} |
coefficient of second term in Fourier expansion of β |

a_{2} |
coefficient of fourth term in Fourier expansion of β |

A | area of rotor disc |

A_{b} |
total blade area (N blades) |

A_{1} |
coefficient of second term in Fourier expansion of β |

A_{2} |
coefficient of fourth term in Fourier expansion of β |

A_{p} |
projected frontal area of rotor head (Chapter 6) |

A_{s} |
flow spoiling factor (Chapter 6) |

A_{z} |
boundary layer shielding factor (Chapter 6) |

b_{1} |
coefficient of third term in Fourier expansion of β |

b_{2} |
coefficient of fifth term in Fourier expansion of β |

B | tip loss factor in r = BR |

B_{1} |
coefficient of third term in Fourier expansion of β |

B_{2} |
coefficient of fifth term in Fourier expansion of β |

c | blade chord |

C_{D} |
drag coefficient |

C_{L} |
lift coefficient |

C_{H} |
H-force coefficient |

C_{P} |
power coefficient |

C_{Q} |
torque coefficient |

C_{T} |
thrust coefficient |

d | differential operator |

D | aerodynamic drag |

e | hinge offset ratio |

f | equivalent flat-plate area |

H | H-force |

I | moment of inertia |

k | empirical constant in expression for profile power |

K | empirical constant in Glauert expression for induced velocity |

l | moment arm of tail rotor thrust about main shaft |

L | aerodynamic lift |

m | blade mass per unit span |

M | figure of merit |

M | Mach number |

M | moment (Figures 8.4 and 8.5) |

M_{T} |
aerodynamic moment about flapping axis |

n | inertia number (Chapter 8) |

N | number of blades |

p | static pressure |

P | power |

q | dynamic pressure, ... |