具有H_2引燃的CH_4、煤油超声速混合的三维数值研究

用双流体模型和分区算法 ,气相多组分N_S方程和液相Euler方程分别用迎风TVD格式和NND格式进行数值求解 ,相间相互作用项方程用二阶Runge_Kutta法求解·　并首次对H2 引燃的CH4 和煤油横向喷射、混合问题进行了数值研究·　结果表明 :与喷射加碘空气的PLIF结果相比 ,本文和实验结果符合得很好·　对直通道 ,后面喷嘴的穿透深度大 ,煤油较气态燃料的穿透深度大 ,但难以被卷吸到喷嘴前的回流区内 ,流场出现无煤油区·　H2 和CH4 均可扩散到回流区内 ,CH4 和煤油引燃机理不同·　对后台阶直通道 ,存在两个回流区 ,H2 可扩散到这两个回流区 ,但CH4 只能被卷吸到其喷嘴前的回流区·　后台阶直通道增强混合的效果和引燃点火的可靠性更好

Numerical Studies on the Mixing of CH_4 and Kerosene Injected Into a Supersonic Flow With H_2 Pilot Injection

Two_fluid model and divisional computation techniques were used. The multi_species gas fully N_S equations were solved by upwind TVD scheme. Liquid phase equations were solved by NND scheme. The phases_interaction ODE equations were solved by 2nd Runge_Kutta approach. The favorable agreement is obtained between computational results and PLIF experimental results of iodized air injected into a supersonic flow. Then, the numerical studies were carried out on the mixing of CH 4 and kerosene injected into a supersonic flow with H 2 pilot injection. The results indicate that the penetration of kerosene approaches maximum when it is injected from the second injector. But the kerosene is less diffused compared with the gas fuels. The droplet free region appears in the flow_field. The mixing mechanism of CH 4 with H 2 pilot injection is different from that of kerosene. In the staged duct, H 2 can be entrained into both recirculation zones produced by the step and injectors. But CH 4 can only be carried into the recirculation between the injectors. Therefore, initiations of H 2 and CH 4 can occur in those regions. The staged duct is better in enhancing mixing and initiation with H 2 pilot flame.