Characterization and prediction of dripping of liquid films flowing underneath planar surfaces and on tilted cylinders

下落液膜在能源和工艺工程中有着广泛的应用。相关文献提供了倾斜或垂直壁和不同表面几何形状上的膜演变和膜转移特性的全面概述。斜面下薄膜的实验和数值数据非常少，尽管它们在诸如涂层问题或化学工程中的结构化填料中很重要。在这些应用中，防止滴落以确保涂层均匀或促进滴落以增加液/气界面面积是非常重要的。由于表面下薄膜的滴落是非线性的，因此很难用分析的方法来解决这个问题，而且目前还没有关于滴落发生和滴落质量流的定量分析方法。在提议的项目中，通过完全解析的数值模拟、低维建模和实验研究，分析了在基本表面几何形状下流动的薄膜的滴水机制。目的是为滴落的开始提供物理动机的相关性，并量化滴落质量流量和比表面积，以便有针对性地设计各自的过程。

Falling liquid films are of technical relevance in a multitude of applications in energy and process engineering. The relevant literature offers a comprehensive overview of film evolution and film transfer properties on inclined or vertical walls and differing surface geometries. Experimental and numerical data of films underneath an inclined plane are very scarce, despite their importance in e.g. coating problems or structured packings in chemical engineering. In these applications, the prevention of dripping to ensure homogeneous coatings or the promotion of dripping to increase liquid/gas interface areas is of high interest. Due to the non-linear character of dripping from films beneath surfaces, an analytical approach to the problem is difficult and correlations for the onset of dripping and a quantification of dripping mass flows are not available at present.Within the proposed project, the dripping regime in films flowing beneath basic surface geometries is analyzed through fully resolved numerical simulation, low-dimensional modeling and experimental investigations. The aim is to provide physically motivated correlations for the onset of dripping and to quantify dripping mass flows and specific surface areas to enable a targeted design of respective processes.