On the deflagration-to-detonation transition (DDT) process with added energetic solid particles for pulse detonation engines (PDE)
On the deflagration-to-detonation transition (DDT) process with added energetic solid particles for pulse detonation engines (PDE)
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DOI：
10.1007/s00193-017-0800-2
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发表时间：
2018-01
期刊：
影响因子：
2.2
通讯作者：
V. B. Nguyen;Jiun-Ming Li;P. Chang;Q. T. Phan;C. Teo;B. Khoo
中科院分区：
文献类型：
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作者：
V. B. Nguyen;Jiun-Ming Li;P. Chang;Q. T. Phan;C. Teo;B. Khoo
采用数值模拟方法研究了含能铝粒子脉冲爆震发动机（PDE）中燃烧转爆轰（DDT）的动力学过程。采用欧拉-拉格朗日方法对含固体铝颗粒的未燃氢气/空气混合物的爆震爆震波传播过程进行了数值研究。混合数值方法结合适当的子模型被用来捕捉气体动力学特性，颗粒的行为，燃烧特性，和双向固体颗粒气体流动的相互作用。在我们的方法中，气体混合物表示在欧拉参考系中，而固体铝颗粒在拉格朗日参考系中被跟踪。使用已发布的基准问题验证了所实现的计算机代码。结果表明，铝颗粒不仅缩短了DDT长度，而且缩短了DDT时间。DDT的改善主要归因于铝颗粒表面化学反应释放的热量。与DDT过程相关的温度高于添加非反应颗粒的情况，伴随着压力的上升。在适当的颗粒体积分数范围内，特别是在本研究中，在爆震室内添加的铝微颗粒体积分数越高，燃烧过程中释放的热能越多，局部高温引起的局部不稳定性越大，从而导致DDT过程越快。实质上，铝颗粒有助于成功地过渡到爆震波的DDT过程，用于其中燃料气体混合物可能太贫或太富的（故障）情况。随着对添加的铝颗粒对DDT和爆震过程的动力学的影响的更好理解，我们可以将其应用于修改爆震室的几何形状（例如，爆震管的长度），从而提高PDE的操作性能。
In this paper, numerical simulations are performed to study the dynamics of the deflagration-to-detonation transition (DDT) in pulse detonation engines (PDE) using energetic aluminum particles. The DDT process and detonation wave propagation toward the unburnt hydrogen/air mixture containing solid aluminum particles is numerically studied using the Eulerian–Lagrangian approach. A hybrid numerical methodology combined with appropriate sub-models is used to capture the gas dynamic characteristics, particle behavior, combustion characteristics, and two-way solid-particle–gas flow interactions. In our approach, the gas mixture is expressed in the Eulerian frame of reference, while the solid aluminum particles are tracked in the Lagrangian frame of reference. The implemented computer code is validated using published benchmark problems. The obtained results show that the aluminum particles not only shorten the DDT length but also reduce the DDT time. The improvement of DDT is primarily attributed to the heat released from surface chemical reactions on the aluminum particles. The temperatures associated with the DDT process are greater than the case of non-reacting particles added, with an accompanying rise in the pressure. For an appropriate range of particle volume fraction, particularly in this study, the higher volume fraction of the micro-aluminum particles added in the detonation chamber can lead to more heat energy released and more local instabilities in the combustion process (caused by the local high temperature), thereby resulting in a faster DDT process. In essence, the aluminum particles contribute to the DDT process of successfully transitioning to detonation waves for (failure) cases in which the fuel gas mixture can be either too lean or too rich. With a better understanding of the influence of added aluminum particles on the dynamics of the DDT and detonation process, we can apply it to modify the geometry of the detonation chamber (e.g., the length of the detonation tube) accordingly to improve the operational performance of the PDE.