Experimental investigation into three-dimensional wavy liquid films under the influence of electrostatic forces
Experimental investigation into three-dimensional wavy liquid films under the influence of electrostatic forces
复制标题
静电力影响下三维波状液膜的实验研究
DOI：
10.1007/s00348-012-1342-0
复制
发表时间：
2012
影响因子：
2.4
通讯作者：
R. Kneer
中科院分区：
文献类型：
--
作者：
W. Rohlfs;G. Dietze;H. Haustein;O. Tsvelodub;R. Kneer
三维界面波，发展的自由表面上的下降液膜是已知的强化传热和传质。在这种背景下，本文研究了静电力施加到降膜的介电液体的三维非线性波动动力学的影响。因此，采用共焦彩色成像方法测量局部膜厚度，并通过摄影表征复杂的波拓扑。实验表明，电场和降膜的流体动力学之间的复杂的相互作用，从而发现静电力在波的不同区域中增加和减少波峰高度。此外，电诱导的三维波阵面的分裂，这导致在流向上的局部倍频，被发现的能力，影响波的拓扑结构展示在这里打开的可能性，以优化在下降液膜的传热过程。
Three-dimensional interfacial waves that develop on the free surface of falling liquid films are known to intensify heat and mass transfer. In this context, the present paper studies the effect of electrostatic forces applied to a falling film of dielectric liquid on its three-dimensional nonlinear wave dynamics. Therefore, measurements of the local film thickness using a confocal chromatic imaging method were taken, and the complex wave topology was characterized through photography. The experiments show a complex interaction between the electric field and the hydrodynamics of the falling film, whereby electrostatic forces were found to both increase and decrease wave peak height in different regions of the wave. Additionally, an electrically induced breakup of the three-dimensional wave fronts, which leads to a locally doubled frequency in streamwise direction, is found. The ability to influence the wave topology demonstrated here opens the possibility to optimize heat transfer processes in falling liquid films.