Notations Flashcards
a
1/rad
Lift curve slope (dCL/d⍺, dCL/dδ)
AR
-
Lifting Surface Aspect Ratio
AR = b^2/S
b
m
Lifting surface span
c
m
Chord length
cs
m/s
Speed of sound
c’/c
-
High-lift device chord extension ratio
_
c
m
Mean Aerodynamic Chord length
_
c = 2 (integrate(c^2 dy/S) between b/2 and 0)
CD
-
Drag Coefficient
CD = CD0 + CDi
CD0
-
Drag Coefficient at zero lift
CDi
-
Lift dependent/induced Drag Coefficient
CDi = CL^2/piARe
CH
-
Hinge Moment Coefficient
CL
-
Lift Coefficient
CL0
-
Lift Coefficient at zero aircraft angle of attack
CM
-
Pitching Moment Coefficient
CM0
-
Pitching Moment Coefficient at zero lift (constant when taken about surface aerodynamic centre)
CT
-
Thrust Coefficient
CT = T/0.5ρV∞^2*S
D
N
Drag Force
D = 0.5ρV∞^2SCD
e
-
Oswald/span efficiency factor
g
m/s^2
Gravitational acceleration
g0 = 9.81 m/s^2
H
N m
Hinge moment
_ H = 0.5*ρ*V∞^2*Ssurf*csurf*CH
Hm
-
Stick-fixed manoeuvre margin
Ixx
kg m^2
Roll second moment of inertia
Ixx = integrate(y^2 + z^2)dm
Iyy
kg m^2
Pitch second moment of inertia
Iyy = integrate(x^2 + z^2)dm
Izz
kg m^2
Yaw second moment of inertia
Izz = integrate(y^2 + x^2)dm
Ixz
kg m^2
Cross second moment of inertia
Ixz = integrate(xz)dm
i
rad
Lifting surface setting angle - defined between mean aerodynamic chord and aircraft z-datum
Kn
-
Stick-fixed static margin
_ _
xnp - xCG
K’n
-
Stick-free static margin
_ _
x’np - xCG
L (N)
N
Lift
L = 0.5ρV∞^2SCL
L (N m)
N m
Rolling Moment (positive port wing up)
lH
m
Horizontal separation between wing and tailplane aerodynamic centres
xH - xW
l’H
m
Horizontal tailplane lift moment arm
xH - xCG
m
kg
Aircraft mass
M
N m
Pitching Moment (positive nose up)
_ M = 0.5*ρ*V∞^2*S*c*CM
M∞
-
Freestream Mach number
M∞ = V∞/cs
n
-
Load factor
n = Lift/Weight
N
N m
Yawing moment (positive port wing forward)
p (Pa)
Pa
Pressure
p0
Pa
Total/Pitot pressure