Ammonia is a promising alternative fuel for CO₂ emission mitigation. The use of ammonia blends allows for more flexibility compared to pure ammonia fuel and is often considered for immediate CO₂ emission reduction in existing facilities running on natural gas. However, fundamental studies on these fuel mixtures remain scarce. This study thus focuses on ammonia/methane blend fuels. The effect of ammonia on methane jet flame stabilization is investigated using a non-premixed jet flame configuration to observe the flame stabilization mechanisms, the flame-burner interactions and how ammonia addition affects the attached flame stabilization up to liftoff. The flame tip position was observed using CH* chemiluminescence. Heat transfer to the burner was monitored by temperature measurement at the burner lip and inside the burner to observe the impact of ammonia addition on thermal interactions. The main stabilization regimes described for the methane non-premixed jet flame are still observed in the case of ammonia addition. However, the transition between those regimes appeared to be shifted toward larger velocities relative to the methane case due to ammonia addition. Those changes could be related to the change in the mixture combustion properties which affects both flame position, heat transfer to the burner and in turn the transition between the identified stabilization regimes. The dynamic leading to liftoff was further analyzed to highlight how ammonia addition perturbated the stabilization balance up to liftoff.

氨是一种很有前景的 CO ₂减排替代燃料。与纯氨燃料相比，使用氨混合物具有更大的灵活性，并且通常被认为是直接使用 CO ₂减少使用天然气的现有设施的排放量。然而，对这些燃料混合物的基础研究仍然很少。因此，本研究侧重于氨/甲烷混合燃料。使用非预混喷射火焰配置研究氨对甲烷喷射火焰稳定的影响，以观察火焰稳定机制、火焰-燃烧器相互作用以及氨添加如何影响附着的火焰稳定直至升空。使用 CH* 化学发光观察火焰尖端位置。通过燃烧器唇缘和燃烧器内部的温度测量来监测到燃烧器的热传递，以观察添加氨对热相互作用的影响。在添加氨的情况下，仍然观察到为甲烷非预混喷射火焰描述的主要稳定机制。然而，由于氨的加入，相对于甲烷情况，这些状态之间的过渡似乎转向更大的速度。这些变化可能与混合物燃烧特性的变化有关，它影响火焰位置、向燃烧器的热传递，进而影响确定的稳定机制之间的过渡。进一步分析了导致升空的动力学，以强调氨的添加如何扰乱稳定平衡直至升空。