低浓度三分子模型差速流动引起的化学不稳定性

建立了低浓度三分子反应模型反应-流动-扩散方程,理论分析了出现差速流动化学不稳定的条件,得到了临界流动速率c和扰动波包的群速度vg,讨论了扰动增长率与流速的关系,并理论研究了出现不稳定时系统的时、空结构.研究结果表明,化学反应在低浓度条件下也可能出现差速流动引起的化学不稳定.

Differential Flow-Induced Chemical Instability in Low-Concentration Brusselator

The reaction-flow-diffusion equation for low-concentration Brusselator is developed and the existence condition for differential flow-induced chemical instability for the model is theoretically analyzed by means of linear stability analysis and the method of steepest descent. The neutral valueФc of flow rateФof autocatalyticy and the group velocity v go perturbation wave packet are derived. The relations of flow rate Фto the perturbation growth rate Reλ is discussed. The temporal structure at different time τ (fixed Ф) and spatial structure with different Ф (fixe dτ) of the system while instability exhibits (Ф>Фc) is numerically studied, respectively. It is shown that the differential flow-induced chemical instability may exhibit and the perturbations propagate along the reactor in terms of periodic wave packet. It is proved that under the condition of low concentration for chemical reactions, the differential flow-induced chemical instability may also exhibit.