An experimental investigation of shear-driven rivulets on a flat plate by using a two-perspective view

Abstract

Shear-driven liquid rivulet flow on a horizontal plate is experimentally investigated. In contrast to publications found in the literature, a two-side view on the rivulet is used to simultaneously capture the side and top view. This enables more accurate measurements of the rivulet dimensions and the subsequent calculation of derived quantities. Throughout the experimental test campaign, the ambient gas velocity and the liquid mass flux are altered. In a first qualitative analysis, the occurring rivulet flow regimes are classified and mapped depending on the gas Reynolds number ReG and the rivulet Weber number We. Furthermore, the goal is to quantify the correlation between characteristic rivulet dimensions and the ambient conditions, with a focus on straight and surging rivulets. The quantitative analysis results in an implicit correlation for the rivulet width and height depending solely on the ambient gas velocity and the rivulet mass flow. The investigation of the rivulet wavelength reveals an analogous dependence on the ambient gas velocity. However, the dependence on the rivulet mass flow changes depending on the rivulet flow regimes.