Steady-state hydrazinium nitroformate (HNF) combustion modeling

Two simplified modeling approaches are used to model the combustion of hydrazinium nitroformate (HNF), N₂H₅·C(NO₂)₃. The condensed phase is treated by high-activation-energy asymptotics. The gas phase is treated by two limit cases: the classical high-activation-energy approximation and the recently introduced low-activation-energy approach. This results in simplification of the gas-phase energy equation, making an (approximate) analytical solution possible. The results of both models are compared with experimental results of HNF combustion. It is shown that the low-activation-energy approach yields better agreement with experimental observations, for example, regression rate and temperature sensitivity, than the high-activation-energy approach.