thickness of thermal layer of the condensed phase, L; mean free path for radiation absorption in the condensed phase, nondimensional
lb
distance away from surface at which heat generation becomes negligible
L
length of cylindrical combustion chamber, L; latent heat of evaporation, L2T−2
m
mass burning rate, ML−2T−1
mg
mass velocity of the gas stream, ML−2T−1
M
Mach number, nondimensional; mass of gas in the chamber, M
p
pressure, ML−1T−2
q
heat flux into the condensed phase, MT−3
Q = Qs + Qg
total heat of combustion/reaction, L2T−2
Qg
heat of combustion/reaction in the gas phase, L2T−2
Qs
heat of reaction in the condensed phase, L2T−2
r
sensitivity parameter, nondimensional
rb
sensitivity parameter, nondimensional
R
Universal gas constant, ML2T−2θ−1N−1
s
relative change of the nozzle cross‐sectional area, nondimensional; correction (Chapter 9), nondimensional; surface temperature in the steady‐state regime at initial pressure (Chapter 9), nondimensional
S
cross‐sectional area of cylindrical combustion chamber, L2
t
time, T
T
temperature, θ; period of oscillations, nondimensional
Tk
reference temperature (Chapter 7), θ
u
propellant linear burning rate, LT−1
ug
dimensional gas velocity normal to the surface, LT−1
up
gas velocity normal to the surface in the combustion products zone (Belyaev model), LT−1
U
response function of burning rate to oscillating pressure, non‐dimensional; mass burning rate dependence on temperature and pressure (Chapter 9), ML−2T−1
v
propellant linear burning rate, nondimensional
vg
gas velocity normal to the surface, nondimensional
vp
gas velocity normal to the surface in the combustion products zone (Belyaev model), nondimensional