自润湿流体液滴在倾斜不混溶液体表面上的铺展动力学研究

采用数值模拟方法研究了自润湿流体液滴的铺展动力学特性。针对不混溶均匀受热液体表面上自润湿液滴铺展的动力学过程,基于润滑理论推导出无量纲方程组。研究了在相同润湿条件下,界面张力敏感系数为正、负时自润湿流体液滴在倾斜的不混溶液体表面上的动力学特性,以及毛细力、热毛细力和重力之间的相互作用。结果表明,界面张力敏感系数通过影响界面张力进而影响液滴的迁移特性。倾斜角增加导致液滴铺展速度增加和接触角减小,液滴因此变得更加扁平。液体基底升高,液体基底上层流体受到固体壁面粘滞力的影响减小,左侧液体在重力作用下流向右侧,导致左侧液体基底高度降低,右侧液体基底高度升高。

Study on Spreading Dynamics of Self-rewetting Liquid Dropping on the Surface of Inclined Immiscible Liquid

The spreading dynamic characteristics of a self-rewetting liquid drop are investigated by numerical simulation.Lubrication theory is used to derive dimensionless equations in view of the dynamics progress of a self-rewetting drop spreading on the surface of another immiscible liquid on a uniformly heated substrate.The dynamic characteristics of the drop are investigated when the sensitivity coefficient of interfacial tension is positive and negative and the interaction among capillary force,thermal capillary force and gravity are studied under the same wetting scenario.The results show that the sensitivity coefficient of interfacial tension affects the migration characteristics of drop by affecting the interfacial tension.The increase of inclination angle results in the increase of drop spreading speed and the decrease of contact angle,so the drop becomes more flat.When the liquid substrate rises,the influence of the viscous force of the solid wall on the upper layer of the liquid substrate decreases,and the liquid on the left side flows to the right side under gravity,resulting in the decrease of liquid substrate height on the left side and the increase of on the right side.