剪切流场中液滴形变模型的理论研究

从力学的角度出发，在由两个同心圆筒形成的旋转剪切流场中，分析油水乳化液中分散相液滴的受力及形变，推导出分散相液滴受力与液滴形变的相互关系。提出了剪切流场中液滴形变的三维力学模型，初步建立了拉伸率、收缩系数和剪切应力之间的关系。结果表明，如果测得液滴破裂的临界拉伸率，就很容易求得液滴破裂的临界剪切应力，从而可以应用分散相液滴的拉伸率或收缩系数来分析剪切对油水分离特性的影响。

Theory Study on Model of Deformation of a Liquid Drop in a Shear Flow

Studies of the behavior of liquid drops in a shear flow are motivated by .fundamental and practical applications in several fields of science and engineering including suspension rheology, emulsification, and mixing. However, a few people make a further investigation on the deformation of liquid drops from mechanical aspects. Through the analysis of the suffering force and deformation of a liquid drop in the discrete phase of oil-water emulsion in a shear flow between coaxial cylinders, the relation of them was deduced, mainly from mechanical aspects. A three-dimensional mechanical model of deformation of a liquid drop was propounded in a shear flow, and the relation among stretching rate, shrinkage coefficient and shear stress were established. The results show that critical shear stress can be attained if the critical stretching rate for drop breakup is determined. Therefore the stretching rate or shrinkage coefficient provides a new way to analyze the shear effect on the oil-water separation efficiency.