Page 65 - Aeronautical Engineer Data Book

52 Aeronautical Engineer’s Data Book
Table 3.4 Continued

Controls-fixed neutral point position on
h n
reference chord.
Control-free neutral point position on reference
h' n
chord.
H Hinge moment. Feedback path transfer function.
Total pressure. Shape factor.
Fin span measured perpendicular to the roll axis.
H F
Controls fixed manoeuvre margin.
H m
Controls free manoeuvre margin.
H" m
Moment of inertia in roll (dimensionless).
i x
Moment of inertia in pitch (dimensionless).
i y
Moment of inertia in yaw (dimensionless).
i z
I" Normalized inertia.
Moment of inertia in roll.
I x
Moment of inertia in pitch.
I y
Moment of inertia in yaw.
I z
J Propeller ratio of advance. Moment of inertia.
j (or i) The imaginary operator ( –1 ).
k Spring stiffness coefficient. Lift-dependent drag
factor. Interference factor.
Centre of pressure coefficient.
k cp
Cavitation number.
k d
Pitch rate transfer function gain constant.
k q
Axial velocity transfer function gain constant.
k u
Normal velocity transfer function gain constant.
k w
k Pitch attitude transfer function gain constant.
k Turbo-jet engine gain constant.
K Feedback gain. Circulation. Bulk modulus.
K Feedback gain matrix.
Circulation at wing mid-section.
K 0
Controls-fixed static stability margin.
K n
Controls-free static stability margin.
K' n
l Lift per unit span.
Disc loading (helicopter).
l d
Fin arm.
l f
Tail arm.
l t
L Lift. Rolling moment. Temperature lapse rate.
Lift due to camber.
L c
Wing lift.
L w
Fin lift.
L F
Tailplane lift.
L T
L Lift due to incidence.
m Mass. Strength of a source or sink (fluid
mechanics). Hydraulic depth.
m' Rate of mass flow.
M Mach number.
Free stream Mach number.
M 0
Critical Mach number.
M crit
M Pitching moment.
Wing–body pitching moment.
M 0
Tailplane pitching moment
M T