Aircraft Propulsion, 2nd Edition

Nomenclature

Latin	Definition	Unit
a	Local speed of sound	m/s, ft/s
a	Semimajor axis of inlet elliptic lip (internal)	m, ft
a	Swirl profile parameter	—
at	Speed sound based on total temperature	m/s, ft/s
A	Area	m2, ft2
An	Projection of area in the normal direction	m2, ft2
A9	Nozzle exit flow area	m2, ft2
Aref	Reference area	m2, ft2
Ao	Inlet (freestream) capture area	m2, ft2
A1	Inlet capture area	m2, ft2
A8, A8geo	Nozzle throat area (geometrical area)	m2, ft2
A8eff	Effective nozzle throat area	m2, ft2
AB	Blocked area (due to boundary layer)	m2, ft2
Ab	Burning area of grain in solid rocket motors	m2, ft2
AE	Effective area	m2, ft2
AHL	Inlet highlight area	m2, ft2
AM	Maximum nacelle area	m2, ft2
Ath	Inlet throat area	m2, ft2
A*	Sonic throat, choked area	m2, ft2
b	Semiminor axis of inlet elliptic lip (internal)	m, ft
b	Swirl profile parameter	—
B	Blockage	—
B	Compressor instability parameter due to Greitzer	—
	Absolute velocity vector in turbomachinery	m/s, ft/s
C	Absolute flow speed, i.e.,	m/s, ft/s
c	Chord length	m, ft
c	Effective exhaust velocity in rockets	m/s, ft/s
c*	Characteristic velocity in rockets	m/s, ft/s
Cr, Cθ, Cz	Radial, tangential, axial velocity components in the absolute frame of reference	m/s, ft/s