Application of μ-PIV for investigating liquid film characteristics in an open inclined microchannel

• Published in: Experimental thermal and fluid science 2013-01, Vol.44, p.90-99
• Main Authors: Anastasiou, Antonios D., Makatsoris, Charalampos, Gavriilidis, Asterios, Mouza, Aikaterini A.
• Format: Article
• Language: English
• Subjects: Applied fluid mechanics; Applied sciences; Biological and medical sciences; Bioreactors; Biotechnology; Chemical engineering; Exact sciences and technology; Falling; Falling film; Film thickness; Fluid dynamics; Fluid flow; Fluidics; Fluids; Fundamental and applied biological sciences. Psychology; Fundamental areas of phenomenology (including applications); Liquid films; Methods. Procedures. Technologies; Micro reactor; Microchannels; Physics; Reactors; Various methods and equipments; Velocimetry; Velocity profiles; μ-PIV
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2012.06.001

[Display omitted] ► We examine the possibility of using a μ-PIV system for investigating the hydrodynamic characteristics of thin liquid films. ► We give data concerning liquid film thickness for various flow rates. ► The data collected was also used for reconstructing the corresponding shape of the interface. ► It was verified that the correlations used in the macroscale are not valid in the microscale. ► It was proved that μ-PIV is suitable for assessing liquid film characteristics in micro-channels. Among the most important variables in the design of falling film microreactors (FFMRs) is the liquid film thickness as well as the interfacial area between gas and liquid phases. The scope of the present work is to investigate the suitability of a micro-Particle Image Velocimetry (μ-PIV), a common optical non-intrusive technique, both for estimating the thickness of the liquid film and for determining the shape of the interface. Experiments were conducted in two open inclined, rectangular microchannels with widths 1200 and 600μm. The results proved that μ-PIV is an effective method for investigating the hydrodynamic characteristics of thin liquid films encountered in FFMRs. It was also found that as the microchannel becomes narrower, for the same normalized mass flow rate thicker films are formed. As it is expected correlations widely used for predicting liquid film thickness are not valid in such small dimensions.