分离压作用下波纹状基底上含活性剂液滴铺展稳定性

针对波纹状基底上含不溶性活性剂液滴的铺展过程,引入受活性剂浓度影响的分离压模型,应用非模态稳定性理论分析液滴铺展稳定性.研究表明:与不计及分离压情形相比,分离压作用下的液滴铺展前沿高度明显下降,液滴铺展速率加快;长波扰动有利于增强液滴的演化稳定性,且随扰动波数增大稳定性增强;然而随短波波数增加,液滴演化稳定性逐渐减弱甚至转变为不稳定;较小波数下(k=3)减小引力强度系数α₁和提高斥力强度系数α₂液滴铺展稳定性增强;而较大波数下(k=30)增大α₁和减小α₂有利于液滴铺展稳定性.

Stability of Liquid Droplet Containing Surfactant over Corrugated Topography Surface under Disjoining Pressure

For an insoluble surfactant-laden droplet spreading on corrugated topography,a disjoining pressure model induced by concentration of surfactant was established. Non-model stability theory was carried out to investigate stability of spreading. It indicates that compared with droplet spreading without disjoining pressure,under disjoining pressure advancing front height of droplet reduce apparently and spreading rate increases which improves stability of spreading. Long perturbation wave is conducive to enhance stability of droplet evolution and stability is enhanced with increasing wave number. However,spreading stability trends to deteriorate and even transit to unstable with increasing wave number of short perturbation waves. Reducing attraction strength coefficient α₁ and increasing repulsion strength coefficient α₂ promote spreading stability at small wave number(k=3). In addition,droplet displays more stable spreading with increasing α₁ and decreasing α₂ at large wave number(k=30).