Université libre de Bruxelles (ULB), Nonlinear Physical Chemistry Unit, CP231, 1050 Brussels, Belgium.
Phys Rev E. 2019 Nov;100(5-1):052213. doi: 10.1103/PhysRevE.100.052213.
The dynamics of A+B→C reaction fronts is studied both analytically and numerically in three-dimensional systems when A is injected radially into B at a constant flow rate. The front dynamics is characterized in terms of the temporal evolution of the reaction front position, r_{f}, of its width, w, of the maximum local production rate, R^{max}, and of the total amount of product generated by the reaction, n_{C}. We show that r_{f}, w, and R^{max} exhibit the same temporal scalings as observed in rectilinear and two-dimensional radial geometries both in the early-time limit controlled by diffusion, and in the longer time reaction-diffusion-advection regime. However, unlike the two-dimensional cases, the three-dimensional problem admits an asymptotic stationary solution for the reactant concentration profiles where n_{C} grows linearly in time. The timescales at which the transition between the regimes arise, as well as the properties of each regime, are determined in terms of the injection flow rate and reactant initial concentration ratio.
当 A 以恒定流速径向注入 B 时，研究了三维系统中 A+B→C 反应前沿的动力学，通过分析和数值两种方法。根据反应前沿位置 r_f、宽度 w、最大局部生成速率 R^{max} 和反应生成的总产物量 n_{C}的时间演化来描述前沿动力学。我们表明，r_{f}、w 和 R^{max} 表现出与在直线和二维径向几何形状中观察到的相同的时间标度，无论是在扩散控制的早期时间限制内，还是在较长时间的反应-扩散-输运范围内。然而，与二维情况不同的是，三维问题存在一个渐近的稳态解，其中反应物浓度分布的 n_{C}随时间呈线性增长。两个区域之间的过渡的时间尺度，以及每个区域的特性，都取决于注入流速和反应物初始浓度比。
