We have studied the front propagation in a one dimensional case of combustion by solving numerically an advection-reaction-diffusion equation. The physical model is simplified so that no coupling phenomena are considered and the reacting fluid is a binary mixture of gases. The compressible flow field is given analytically. We analyse the differences between popular models used in fundamental studies of compressible combustion and biological problems. Then, we investigate the effects of compressibility on the front interface dynamics for different reaction types and we characterise the conditions for which the reaction stops before its completion.
Effective rates in dilute reaction-advection systems for the annihilation process $A + A \to \varnothing$
考虑了由流体流动输送的反应颗粒的稀体系。当粒子在有限的相互作用半径内时,它们以给定的速率作为$A + A \to \varnothing$反应。该系统中描述的联合n点的数量的空间密度,它是服从一个层次的传输方程。通过使用拉格朗日方法,其中沿非反应轨迹执行统计平均,在稀或长时间限制中获得解析解。在这个限制,它表明,粒子数的时刻有一个指数衰减,而不是代数预测的标准平均场方法。有效的反应速率,然后相关的拉格朗日对统计的大偏差原则。引入一个唯象模型来研究有效速率作为相互作用长度、动力学的混沌程度和载流子流的可压缩性的函数的定性行为。精确的计算,通过费曼-卡茨的方法,在一个光滑的,可压缩的,随机增量相关的时间高斯速度场支持所提出的启发式方法。
Harvard University(哈佛大学);School of Mathematics Northwestern University of China(西北大学数学学院);University of Rome Tor Vergata(罗马托尔维加塔大学);Eindhoven University of Technology(埃因霍温理工大学);CNR-IAC(意大利国家研究委员会应用计算研究所)