Transient Burning Characteristics of JA2 Propellant Using Experimentally Determined Zel'dovich Map

Abstract

Combustion characteristics of JA2 propellant were studied both experimentally and theoretically. Its steady-state burning behavior was investigated using an optical strand burner. The parameters measured were the regression rate, subsurface temperature profile, and burning surface temperature at different initial temperatures (-40<T i <80°C) and pressures (0.1<P<68 MPa). The measured burning rates r b were correlated as a function of T i and pressure up to 300 MPa. Predicted r b from the correlation are in close agreement with experimental data. The temperature sensitivity σ p was found to decrease as pressure increases, reaching an asymptotic value of 0.0024 K -1 at high pressures. Surface-temperature data were correlated as a linear function of pressure with temperature-dependent coefficients. The Zel'dovich map was constructed from the experimental data. This map was then used in a computer simulation to investigate the transient burning characteristics of JA2 under different pressurization rates. From the simulation results, it was found that JA2 propellant only exhibits a mild transient burning effect. This finding is further confirmed with the observations obtained from a parallel experimental study using an interrupted burner coupled with a real-time X-ray radiography. The reason for this finding is the low value of σ p and its rapid decay as the pressure increases for P < 20 MPa.