Pressure-coefficient trends for mixed propellants

Spline fitting has been used in processing measurements on the pressure dependence of the burning rate to obtain additional information on the variation in the pressure coefficient $\nu$ as affected by grain size and composition, as well as by the nature of the components. Conclusions are drawn on the burning mechanism. The peak on $\nu(p)$ is due to serial-parallel conversion of APC in the condensed and gas phases and to changes in the relative significance of the chemical stages. There is a minimum at elevated pressures for many propellants, which in some cases is transformed into a plateau or inflection on account of interaction between the fuel and the oxidizing agent in the diffusion-kinetic hydrocarbon flame.