The role of low temperature chemistry in combustion mode development under elevated pressures

摘要: Negative Temperature Coefficient (NTC) behavior is an essential feature of low-temperature oxidation for large hydrocarbon fuels, which particular relevance to cool flame and auto-ignition. In this study, using n-heptane as a typical fuel exhibiting NTC, combustion phenomena involving both auto-ignition propagation are computationally studied at initial temperatures within above NTC regime under elevated pressures in one-dimensional planar constant-volume configuration, with detailed kinetics transport. Multi-staged structures representing hot observed, consequently, different types identified during two-staged single-staged scenarios by varying temperature. Specially, the temperature increases, gradually suppressed position transferred from location ahead front end-wall region, leading modes peak pressure magnitudes. Moreover, attributed chemical reactivity processed flame, cases even faster than those beyond regime. A recently developed Livengood–Wu integral further utilized predict these scenarios, yielding good agreement demonstrating significant role chemistry modifying thermodynamic state upstream reaction front. Finally, knocking intensity calculations summarized non-dimensional diagrams, suggest that higher does not guarantee intensity, instead, developing detonation wave initiated occurring could induce comparison thermal explosion