Notations Flashcards
1
Q
a
A
1/rad
Lift curve slope (dCL/d⍺, dCL/dδ)
2
Q
AR
A
-
Lifting Surface Aspect Ratio
AR = b^2/S
3
Q
b
A
m
Lifting surface span
4
Q
c
A
m
Chord length
5
Q
cs
A
m/s
Speed of sound
6
Q
c’/c
A
-
High-lift device chord extension ratio
7
Q
_
c
A
m
Mean Aerodynamic Chord length
_
c = 2 (integrate(c^2 dy/S) between b/2 and 0)
8
Q
CD
A
-
Drag Coefficient
CD = CD0 + CDi
9
Q
CD0
A
-
Drag Coefficient at zero lift
10
Q
CDi
A
-
Lift dependent/induced Drag Coefficient
CDi = CL^2/piARe
11
Q
CH
A
-
Hinge Moment Coefficient
12
Q
CL
A
-
Lift Coefficient
13
Q
CL0
A
-
Lift Coefficient at zero aircraft angle of attack
14
Q
CM
A
-
Pitching Moment Coefficient
15
Q
CM0
A
-
Pitching Moment Coefficient at zero lift (constant when taken about surface aerodynamic centre)
16
Q
CT
A
-
Thrust Coefficient
CT = T/0.5ρV∞^2*S
17
Q
D
A
N
Drag Force
D = 0.5ρV∞^2SCD
18
Q
e
A
-
Oswald/span efficiency factor
19
Q
g
A
m/s^2
Gravitational acceleration
g0 = 9.81 m/s^2
20
Q
H
A
N m
Hinge moment
_ H = 0.5*ρ*V∞^2*Ssurf*csurf*CH
21
Q
Hm
A
-
Stick-fixed manoeuvre margin
22
Q
Ixx
A
kg m^2
Roll second moment of inertia
Ixx = integrate(y^2 + z^2)dm
23
Q
Iyy
A
kg m^2
Pitch second moment of inertia
Iyy = integrate(x^2 + z^2)dm
24
Q
Izz
A
kg m^2
Yaw second moment of inertia
Izz = integrate(y^2 + x^2)dm
25
Ixz
kg m^2
Cross second moment of inertia
Ixz = integrate(xz)dm
26
i
rad
Lifting surface setting angle - defined between mean aerodynamic chord and aircraft z-datum
27
Kn
-
Stick-fixed static margin
_ _
xnp - xCG
28
K'n
-
Stick-free static margin
_ _
x'np - xCG
29
L (N)
N
Lift
L = 0.5*ρ*V∞^2*S*CL
30
L (N m)
N m
Rolling Moment (positive port wing up)
31
lH
m
Horizontal separation between wing and tailplane aerodynamic centres
xH - xW
32
l'H
m
Horizontal tailplane lift moment arm
xH - xCG
33
m
kg
Aircraft mass
34
M
N m
Pitching Moment (positive nose up)
_
M = 0.5*ρ*V∞^2*S*c*CM
35
M∞
-
Freestream Mach number
M∞ = V∞/cs
36
n
-
Load factor
n = Lift/Weight
37
N
N m
Yawing moment (positive port wing forward)
38
p (Pa)
Pa
Pressure
39
p0
Pa
Total/Pitot pressure
40
ps
Pa
Static pressure
41
p (rad/s)
rad/s
Roll rate (positive port wing up)
42
q
rad/s
Pitch rate (positive nose up)
43
q∞
Pa
Dynamic head/pressure
q∞ = 0.5*ρ*V∞^2
44
r
rad/s
Yaw rate (positive port wing forward)
45
S
m^2
Lifting Surface Planform Area
46
T
N
Thrust
47
Td
s
Damped Period of Oscillation
Td = 2pi/ωd
48
Tn
s
Undamped Period of Oscillation
Td = 2pi/ωn
49
U
m/s
Velocity along x wind axis (positive moving forward)
50
V
Velocity along y wind axis (positive moving starboard)
51
V∞
m/s
True Freestream Velocity
V∞ = sqrt(U^2 + V^2 + W^2)
52
Vi
m/s
Equivalent Freestream Velocity
Vi = sqrt(σ)*V∞
53
_
V
-
Non-dimensional Velocity
Vi/VimD
54
_
VH
-
Horizontal tailplane volume coefficient
_ _
(xH - xW) * SH/Sref
55
_
V'H
-
Modified Horizontal tailplane volume coefficient
_ _
(xH - xCG) * SH/Sref
56
_
VV
-
Vertical tailplane volume coefficient
_ _
(xV - xCG) * SV/Sref
57
W (m/s)
m/s
Velocity along z wind axis (positive moving downwards)
58
W (N)
N
Aircraft Weight
59
x
m
Distance aft of aircraft datum, parallel to freestream velocity vector
60
xac
m
Chordwise position about which surface dCM/dCL = 0
61
xnp
m
Distance of stick-fixed neutral point aft of aircraft datum, parallel to freestream velocity vector
62
x'np
m
Distance of stick-free neutral point aft of aircraft datum, parallel to freestream velocity vector
63
xW
m
Distance of wing aerodynamic centre aft of aircraft datum, parallel to freestream velocity vector
64
X
N
Force along x wind axis (positive forward)
65
y
m
Spanwise distance port of aircraft datum, normal to the x - z plane
66
Y
N
Force along y wind axis (positive to starboard)
67
z
m
Distance above aircraft datum, normal to the freestream velocity vector
68
Z
N
Force along z wind axis (positive downwards)
69
⍺
rad
Angle of attack, defined between freestream velocity and aircraft z-datum
70
⍺0
rad
Lifting surface zero-lift angle of attack
71
β
rad
Sideslip angle, defined between freestream velocity and aircraft centreline
72
γ
rad
Climb angle, defined between freestream velocity and the earth frame (positive in a climb)
73
Γ
deg
Dihedral angle
74
δ
rad
Control surface deflection
75
ε
rad
Downwash/upwash angle
76
ε0
rad
Downwash/upwash angle at zero aircraft angle of attack
77
є
rad
Thrust setting angle - defined between thrust line and aircraft z-datum
78
ζ
-
Damping ratio
79
η
-
Lifting surface aerodynamic efficiency factor
η = (Vlocal / V∞)^2
80
Θ
rad
Pitch angle - defined between wind body-fixed axes and the earth frame (positive in the climb)
81
λ
-
Eigenvalue
82
Λ
rad
Lifting surface sweep angle (typically at quarter-chord line)
83
ρ
kg/m^3
Density of air
84
Φ
rad
Roll angle - defined between wind body-fixed axes and the earth frame (positive in the right roll)
85
Ψ
rad
Yaw angle - defined between wind body - fixed axes and the earth frame (positive in the right turn)
86
ω
rad/s
Angular velocity
87
ωd
rad/s
Damped natural angular frequency of oscillation
88
ωn
rad/s
Undamped natural angular frequency of oscillation
ωd = ωn * sqrt(1 - ζ^2)
89
(⋅)A
Property relating to aileron
90
(⋅)C
Property relating to canard
91
(⋅)CG
Centre of Gravity
92
(⋅)e
Property at equilibrium value
93
(⋅)E
Property relating to elevator
94
(⋅)H
Property relating to horizontal tailplane
95
(⋅)R
Property relating to rudder
96
(⋅)ref
Aircraft reference value
_ _
typically Sref = SW, cref = cW
97
(⋅)T
Property relating to trim-tab
98
(⋅)V
Property relating to vertical tailplane
99
(⋅)W
Property relating to main lifting surface (wing)
