Brau Fabian, Schuszter G, De Wit A
Université libre de Bruxelles (ULB), Nonlinear Physical Chemistry Unit, CP231, 1050 Brussels, Belgium.
Phys Rev Lett. 2017 Mar 31;118(13):134101. doi: 10.1103/PhysRevLett.118.134101.
The dynamics of A+B→C fronts is analyzed theoretically in the presence of passive advection when A is injected radially into B at a constant inlet flow rate Q. We compute the long-time evolution of the front position, r_{f}, of its width, w, and of the local production rate R of the product C at r_{f}. We show that, while advection does not change the well-known scaling exponents of the evolution of corresponding reaction-diffusion fronts, their dynamics is however significantly influenced by the injection. In particular, the total amount of product varies as Q^{-1/2} for a given volume of injected reactant and the front position as Q^{1/2} for a given time, paving the way to a flow control of the amount and spatial distribution of the reaction front product. This control strategy compares well with calcium carbonate precipitation experiments for which the amount of solid product generated in flow conditions at fixed concentrations of reactants and the front position can be tuned by varying the flow rate.
在存在被动平流的情况下，当以恒定入口流速(Q)将(A)径向注入(B)中时，从理论上分析了(A + B→C)前沿的动力学。我们计算了前沿位置(r_f)、其宽度(w)以及产物(C)在(r_f)处的局部生成速率(R)的长时间演化。我们表明，虽然平流不会改变相应反应 - 扩散前沿演化的著名标度指数，但其动力学却受到注入的显著影响。特别地，对于给定体积的注入反应物，产物的总量随(Q^{-1/2})变化，而对于给定时间，前沿位置随(Q^{1/2})变化，这为反应前沿产物的量和空间分布的流动控制铺平了道路。这种控制策略与碳酸钙沉淀实验相比效果良好，在碳酸钙沉淀实验中，在反应物固定浓度的流动条件下生成的固体产物量和前沿位置可以通过改变流速来调节。
