详细化学反应模型中温度修正项特性研究

Study on the chemical reaction kinetics of detonation models

本研究主要讨论了爆轰过程中混合气体比热比的变化、详细化学反应模型中温度修正项的函数表达形式、以及活化能对化学反应动力学特性的影响.通过对传统Arrhenius定律的分析完善,提出了具有温度指数修正的总包一步爆轰计算模型.采用几个常用的爆轰计算模型,对满足化学当量比的H2/Air混合气体,开展了爆轰特性的数值模拟对比研究.计算结果表明,新提出的爆轰计算模型能够得到的胞格尺度与实验值符合良好,首次实现了爆轰波胞格尺度的定量数值模拟.论文进一步建立了总包反应模型与详细化学反应模型之间的关系,讨论了详细化学反应模型中温度修正项的物理意义.

In this paper, the influences of specific heat ratio, the modification term in the detailed reaction kinetics, and the activation energy on the properties of chemical reaction kinetics of detonation models are studied. The results first demonstrate that the temperature power function to modify the chemical reaction rates of detailed chemical reaction kinetics should be replaced by a temperature exponential function, which is produced by the variation of specific heat ratio during the reaction process, physically. A new overall one-step detonation model with variable specific ratio and gas constant is proposed to improve the property of Arrhenius law. Two dimensional numerical simulations with this new model are conducted, and the detonation cell sizes are in agreement with experimental results quantitatively.