A review of calculations for unsteady burning of a solid propellant.

A = E(l T^ admittance function, Eq. (1) sensitivity of gas phase to pressure changes specific heats of solid and gas activation energy for surface reaction E = ES/RTS enthalpy latent heat for surface reaction; Hp > 0 for exothermic s_urface reaction H = Hp/cT average mass flux fluctuation of mass flux at the surface index in the linear burning rate law, r = ap index in the surface pyrolysis law, Eq. (25) average heat release (per unit volume) in solid heat release in gas phase fluctuations of heat transfer at the average position of the surface, x = 0 fluctuations of heat release at the burning surface linear burning rate universal gas constant initial temperature of propellant, x -*• — co temperature of burning surface flame temperature average chamber temperature, x -*+ °° surface displacement, velocity functions defined in Eqs. (22) and (27) functions defined in Eqs. (22) and (27) stands for p'/p Eqs. (17-20) thermal conductivities of solid and gas stands for (ms'/m)r density of solid propellant and gas phase average density in chamber normalized temperature or a time lag dimensionless frequency parameters for the solid and gas phases; Eqs. (18) and following Eq. (34) real angular frequency mean value fluctuating value evaluated at the solid-gas interface evaluated on the gas (+) or solid ( — ) side evaluated on the gas or solid side of the mean position of the burning surface evaluated at the flame, or just downstream of the flame real part imaginary part