Spatio-temporal energy release behavior in Al-rich PTFE/Al reactive jet formation

To investigate the reaction evolution during the reactive Al-rich PTFE/Al jet formation process, a multi-cabin vented chamber energy harvesting system was employed to measure the overpressure characteristics of the reactive jet. Combined with numerical simulations, the spatio-temporal energy release behavior was revealed, and the timing sequence reaction mechanism was elucidated. On this basis, an evaluation method based on the multi-cabin vented chamber was proposed, enabling decoupled and quantitative characterization of the penetration–explosion energy release behavior of reactive jets. The results indicate that, when flowing to a certain extent, reactive jets possess the capacity for self-activation, thereby inducing an ignition reaction. Following a stage of reaction growth, it evolves into overall deflagration. The ignition expands axially from the slug toward the jet head and radially outward from the central axis. The combined effects of temperature rise and the localized enrichment of Al particles in the slug region are likely the key mechanisms triggering ignition. Evaluation calculation results indicate that the actual energy released by the reactive jet during the formation process accounts for about 47.3% of the theoretical value. Analysis suggests that during initial shorter-range flow distance (0∼9.2CD), energy release of the reactive jet is not obvious and the energy dissipation is negligible, whereas during longer-range flow distance (9.2CD∼12.5CD), significant ignition occurs, causing lateral jet divergence and resulting in significant reactive energy loss.