C	specific heat capacity [J/kg/K]
$D$	diffusion coefficient [m2/s]
$E$	activation energy [J/mol]
$g$	gravity acceleration [m/s2]
$k$	preexponential factor [s−1]
$M$	molar mass [g/mol]
$\dot{m}$	mass burning rate [g/s]
$n$	pyrolysis reaction order [-]
$p$	pressure [Pa]
$Q$	heat release [J/kg]
$q$	heat flux [W/m2]
$R_0$	universal gas constant [J/mol/K]
$T$	temperature [K]
$t$	time [s]
$u$	velocity [m/s]
$W$	reaction rate [s−1]
$x$	coordinate along fuel surface [m]
$Y$	gas component mass fraction [-]
$y$	coordinate normal to fuel surface [m]
Greek symbols
$\mathsf{\alpha }$	conversion degree [-]
$\gamma$	solid component mass fraction [-]
$\delta$	burnout degree [-]
$\mathsf{\eta }$	solid component volume fraction [-]
$\mathsf{\lambda }$	thermal conductivity [W/m/K]
$\mathsf{\mu }$	dynamic molecular viscosity [kg/m/s]
$\mathsf{\nu }$	stoichiometric coefficient [-]
$\mathsf{\rho }$	density [kg/m3]
$\tau$	half-thickness [m]
$\mathsf{\Psi }$	inhibition effect coefficient
Subscripts
$a$	ambient
$b$	binder
$F$	fuel
F	fiber
$g$	gas
$I$	inert component
$O$	oxidizer
$P$	product
$p$	pyrolysis
$s$	solid
Superscripts
$r$	radiative
$x$	along fuel surface
$y$	normal to fuel surface