不同尺度上的混和对于快速化学反应过程的影响

EFFECTS OF MIXING ON VARIOUS SCALES ON FAST CHEMICAL REACTIONS

着重阐明液相混和过程中不同尺度上的湍流运动对快速化学反应的影响机理，并提出了一套相应的理论框架来描述湍流混和与化学反应。

Fast chemical reactions in liquid phase usually involve turbulent mixing on three scales:micromixing,turbulent diffusion,bulk convection or circulation.This paper aims to elucidatemixing mechanisms on various scales and the influences on fast chemical reactions on the basis ofthe previous serial works of the authors.It is concluded that on the small scale,deformation of fluidelement is the critical step in micromixing,and its effect on fast reactions can be represented by theDamkohler number Da;on the mesoscale,turbulent diffusion will become the rate-determining stepof mixing under the condition of Li≤Li_(crit) ,and the effect is represented by the number Li; while onthe large scale,the bulk flow will also give effect on the reac tions by means of transporting thereaction zone away,and the effect is represented by the Reynolds number Re. An integraldescription of turbulent mixing with fast chemical reactions was formulated in this paper.It wasshown that the model can effectively simutate the reactor’s behaviors,and its accuracy relies ondetailed knowledges of spatial distribution of turbulent parameters.