论文标题
多压指数γ对气态爆炸结构的影响
The Effect of the Polytropic Index γ on the Structure of Gaseous Detonations
论文作者
论文摘要
本研究旨在阐明多粒子指数（即，在完美气体的背景下的特定热量之比）对爆炸结构的影响。这是通过二维数值模拟来解决的。为了简化煤气动物的作用，化学模型使用了简单的Arrhenius动力学定律。通过冲击温度归一化的激活能在所有被考虑的混合物中保持对温度的相同反应速率敏感性。该过程将煤气动力效应与化学效应分离。数值结果表明，在低多粒子的混合物中，与较高的多粒子的混合物相比，对流混合的增强是增强的。使用拉格朗日示踪剂评估混合。此外，发现具有低多性反应的混合物的反应长度比具有高多粒子的混合物较短。同样，对于本研究中考虑的参数范围，结果表明，射流引起的爆炸中的马赫茎分叉主要是一种气体动力驱动的机制。
The present study aims to clarify the effect of the polytropic index (i.e., the ratio of specific heats in the context of a perfect gas) on the detonation structure. This is addressed by two-dimensional numerical simulations. To ease the clarification of the role of gasdynamics, a simple Arrhenius kinetic law is used for the chemical model. The activation energy, normalized by the shock temperature, is kept constant to obtain the same reaction rate sensitivity to temperature in all considered mixtures. This procedure dissociates the gasdynamic effects from the chemistry effects. The numerical results reveal that in mixtures with low polytropic indicies, the convective mixing is enhanced compared to mixtures with higher polytropic indicies. The mixing is evaluated using Lagrangian tracers. Moreover, mixtures with low polytropic indicies are found to have a shorter reaction length than mixtures with high polytropic indicies. Also, for the range of parameters considered in this study the results indicate that Mach stem bifurcation in detonations due to jetting is primarily a gasdynamic driven mechanism.
