铝粉燃料水冲压发动机在水下高速推进和空水跨介质领域展现出广阔应用前景，然而过大的粉末喷注速度会导致燃烧室内部火焰无法驻定甚至吹熄。通过试验和数值模拟手段探究了铝粉燃料水冲压发动机的火焰吹熄特性，旨在为发动机的稳定点火工作范围界定以及粉末喷注速度设计提供指导。研究表明，在当前试验工况下发动机近吹熄极限为48 m/s。增加粉末喷注速度降低了颗粒与周围水蒸气掺混度以及氧燃比。在50 m/s低速吹熄工况下，一次进水口前方火焰短暂存在，随后发生吹熄；而60 m/s高速吹熄工况下火焰形成后直接被吹离燃烧室。建立了基于Damk?hler数(Da)的颗粒点火条件分析方法，发现随着喷注速度提高，颗粒Da数下降；稳定火焰工况下点火潜力高于60%，近吹熄时则降至43.6%。近吹熄条件下Da数的典型特征为“端点分布模式”，即低Da数占比显著上升，高Da数颗粒急剧减少，而中值区间变化相对较小。

Aluminum powder-fueled water ramjet engines demonstrate promising application potential in high-speed underwater propulsion and air-water trans-medium vehicles. However, excessively high powder injection velocities may prevent flame stabilization in the combustion chamber and even lead to blow-off. This study investigates the flame blow-off characteristics of such engines through experimental and numerical methods, aiming to delineate the stable ignition operating range and provide guidance for the design of powder injection velocities. The results indicate that the near-blow-off limit under the current experimental conditions is 48 m/s. In-creasing the injection velocity reduces the mixing efficiency between aluminum particles and surrounding steam as well as the local oxygen-fuel ratio. Under the low-velocity blow-off condition of 50 m/s, a transient flame is established ahead of the primary water inlet before eventual blow-off occurs. In contrast, at the high-velocity blow-off condition of 60 m/s, the flame is directly expelled from the combustor once formed. A particle ignition analysis method based on the Damk?hler number (Da) was established, reveal-ing that the average Da number decreases with increasing injection velocity. The ignition potential remains above 60% under stable flame conditions but drops to 43.6% near the blow-off limit. A characteristic “end-cluster distribution pattern” of Da numbers is observed near blow-off condition, manifested by a significant increase in low-Da particles, a sharp decrease in high-Da particles, and relatively slight variation in the mid-range Da values.