稳态双曲流场中液/液混合的粘性液滴哑铃分散模型

A DUMBBELL DISPERSION MODEL OF VISCOUS DROPS OF LIQUID/LIQUID MIXING IN STEADY STATE PLANE HYPERBOLIC FLOW FLUIDS

通过对稳态双曲流场中液／液混合体系分散相液滴所受分散作用力的分析，建立了粘性液滴的哑铃分散模型．趋于将两粘性液滴分开的分散作用力与粘度比、流场类型和强度、液滴半径、哑铃取向和尺寸有关．该模型解释了流场类型与分散作用的关系．流场类型对液滴的分散具有很大影响，在纯应变拉伸流场中分散作用力是简单剪切流场中的两倍，因而对于液滴的分散，拉伸流场较简单剪切流场更有效，这与以前的实验结论符合．

Many industrial processes involve dispersion of immiscible liquids into a blend. Since the mixing equipment and conditions play an essential role on the morphology of a blend,it is important to realize dispersed processes. A dumbbell dispersion model of viscous drops is established according to the analysis of the dispersed force to the drops of a liquid/liquid mixing system in steady state plane hyperbolic flow fields. The dispersed force is a function of viscosity ratio, flow type and its intensity, drops radius, orientation and size of the dumbbell. The model reveals the relation between dispersed force and the types of flow fields. Different flow fields exert great different effects on the dispersion of drops. The dispersed force in an elongation flow is double what it is in a simple shear flow. This shows that the elongation flow is more efficient than the shear flow in dispersion, which agrees with the results of former experiments. The model converts to the rigid particle dumbbell model when viscosity ratio tends to infinite.