Study on the Flame Acceleration and Transition from Deflagration to Detonation of N₂O/C₂H₄/CO₂

Abstract

The application of nitrous oxide (N 2 O) as a candidate oxidant provides new opportunities for green propellants and propulsion systems. In this study, flame propagation, acceleration, and transition to detonation characteristics of stoichiometric N 2 O/C 2 H 4 diluted with CO 2 were investigated in 2 m cylindrical channels at 1 atm and 293 K. The flame propagation and acceleration were monitored by a high-speed video. Pressure transducers were located at different positions along the channel to collect data concerning DDT and detonation development. The in-fluence rules of various mass fractions of CO 2 on the above performance were evaluated. The results indicated that the process of flame propagation for N 2 O/C 2 H 4 was divided into three stages, ignition stage, DDT and detonation stage. Both the process of flame acceleration (FA) and peak overpressure for all the test mixtures decreased with an increase of CO 2 concentration in the initial stage, and detonation wave propagation was stabilized with the increase of CO 2 , then the corresponding propagation velocity was close to the CÀ J velocity.