Kovalchuk N M, Vollhardt D
Institute of Biocolloid Chemistry, 03142 Kiev, Ukraine.
J Phys Chem B. 2005 Aug 11;109(31):15037-47. doi: 10.1021/jp0519619.
The effect of buoyancy on spontaneous repeated nonlinear oscillations of surface tension, which appear at the free liquid interface by dissolution of a surfactant droplet under the interface, is considered on the basis of direct numerical simulation of the model system behavior. The oscillations are the result of periodically rising and fading Marangoni instability. The buoyancy force per se cannot lead to the oscillatory behavior in the considered system, but it influences strongly both the onset and decay of the instability and therefore, affects appearance and characteristics of the oscillations. If the surfactant solution density is smaller than the density of the pure liquid, then the buoyancy force leads to a considerable decrease of the induction period and the period of oscillations. The buoyancy force affects also the dependence of the oscillation characteristics on the system dimensions. The results of the simulations are compared with the available experimental data.
基于对模型系统行为的直接数值模拟，研究了浮力对表面张力自发重复非线性振荡的影响，这种振荡是由表面活性剂液滴在界面下溶解时在自由液体界面处出现的。这些振荡是周期性上升和衰减的马兰戈尼不稳定性的结果。浮力本身不会导致所考虑系统中的振荡行为，但它会强烈影响不稳定性的起始和衰减，因此会影响振荡的出现和特性。如果表面活性剂溶液的密度小于纯液体的密度，那么浮力会导致诱导期和振荡周期显著缩短。浮力还会影响振荡特性对系统尺寸的依赖性。将模拟结果与现有的实验数据进行了比较。
