The blowout characteristics of partially premixed flame during the condition transition in a cavity-stabilized scramjet combustor are investigated by the experimental method. More attention is placed on the unsteady evolution of the turbulent jet flame, as well as its dynamic response with the initial reactive flow states. The Mach number of flow at the entrance of the combustor is 2.52, the total pressure and the stagnation temperature of which are 1.6 MPa and 1486 K. The cavity-stabilized jet flame is blown out once the injection pressure drop reaches a critical value. During the flame blowout process, the most strongly reactive region gradually transits from vicinity of the cavity shear layer to downstream. Accompanied the sharply decrease of combustion intensity, the light intensity drops rapidly until the flame is completely extinguished. The experimental results indicate that the dynamic process of flame blowout depends on the initial reactive flowfields. The jet flame lasts longer and more intermediate products with high temperature reside within the combustor, which is beneficial to ignite the combustible fuel mixed in the air. As the increase of initial combustion intensity, the flame can be maintained in the combustor at a lower limit of global equivalence ratio after the condition transition. The results on the flame blowout limits are of great significance for the design of the condition transition in a scramjet.

采用实验方法研究了空腔稳定超燃冲压发动机燃烧室状态转变过程中部分预混火焰的爆燃特性。更多的注意力放在湍流喷射火焰的非稳态演化，以及它对初始反应流状态的动态响应上。燃烧器入口处的流动马赫数为2.52，总压力和驻点温度分别为1.6 MPa和1486 K。当喷射压降达到临界值时，空腔稳定射流火焰被吹灭。在火焰熄灭过程中，反应最强的区域逐渐从腔体剪切层附近过渡到下游。伴随着燃烧强度的急剧下降，光强度迅速下降，直至火焰完全熄灭。实验结果表明，火焰熄灭的动态过程取决于初始反应流场。喷射火焰持续时间更长，更多的高温中间产物留在燃烧器内，有利于点燃混合在空气中的可燃燃料。随着初始燃烧强度的增加，条件转变后燃烧室中的火焰可以保持在全局当量比的下限。火焰熄灭极限的结果对超燃冲压发动机的状态转换设计具有重要意义。有利于点燃混合在空气中的可燃燃料。随着初始燃烧强度的增加，条件转变后燃烧室中的火焰可以保持在全局当量比的下限。火焰熄灭极限的结果对超燃冲压发动机状态转变的设计具有重要意义。有利于点燃混合在空气中的可燃燃料。随着初始燃烧强度的增加，条件转变后燃烧室中的火焰可以保持在全局当量比的下限。火焰熄灭极限的结果对超燃冲压发动机的状态转换设计具有重要意义。