聚心火焰在共振腔作用下引发爆轰的数值研究

 基于带化学反应的二维轴对称Euler方程，利用带有Superbee限制函数的波传播算法，对共振腔中的氢气-空气预混气的聚心燃烧进行了数值模拟，讨论了共振腔不同抛物面对起爆的影响。数值结果表明，在开始阶段，燃烧诱导的激波在轴心、火焰和固壁的反射，使火焰失稳，随后共振腔中的抛物壁面上产生一定频率和强度的反射激波，不断穿越火焰，使火焰进一步失稳，加剧了燃烧速度，最终导致爆轰的形成。同时，火焰在与激波的作用过程中，形状扭曲变形，呈封闭端小敞口端大的扁平头部蘑菇云。共振腔抛物面的不同形状引起激波聚焦位置的变化，会影响激波和火焰的相互作用，使起爆提前或推迟，甚至不起爆。

Numerical Investigations of Detonation Induced by Implosion Flame in Resonator Cavity

Based on the two-dimensional axisymmetric Euler equations coupling with chemical reactions,the phenomena of implosion combustion for hydrogen-air mixture were numerically studied by using wave propagation algorithm with Superbee limiter in resonator cavity.The effects of resonator shapes on initiation and detonation were discussed.Results show that the shock wave induced by combustion firstly reflected back and forth from walls and the axis of the resonator cavity,which led to multiple the shock-flame interactions and enhanced the flame combustion.Then the reflected shock wave produced by the parabolic reflector in resonator cavity frequently penetrated the flame,which led to continuous flame excitation.Finally,DDT occurred.Simultaneously,the repeated shock-flame interactions caused the instability and distortion of the flame,and then formed asymmetrical collapsing of the flame front.The different shapes of reflector caused the change of focus,which could influence the shock-flame interaction and made detonation onset change,even not occurred.