Measurement of water falling film thickness to flat plate using confocal chromatic sensoring technique

• Published in: Experimental thermal and fluid science Vol. 33; no. 2; pp. 273 - 283
• Main Authors: Zhou, D.W., Gambaryan-Roisman, T., Stephan, P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.01.2009; Elsevier
• Subjects: CORRELATIONS; ENGINEERING; Exact sciences and technology; Falling liquid film; Falling liquid films; Film thickness; FLUCTUATIONS; Fluid dynamics; Fundamental areas of phenomenology (including applications); Hydrodynamic waves; Instrumentation for fluid dynamics; Interfacial waves; LAMINAR FLOW; ORIENTATION; Physics; PLATES; REYNOLDS NUMBER; THICKNESS; WATER; Falling liquid film; Laminar flow; Film thickness; Interfacial waves; Confocal system; Measuring methods; Instrumentation; Falling film; Optical systems; Experimental study; Layer thickness; Inclination; Film flow; Free surface flow; Flat plate
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2008.09.003

An experimental investigation of wavy water film falling down a flat plate has been carried out using confocal chromatic sensoring technique to determine the instantaneous and statistical characteristics of the film. The experiments involved three parameters: liquid feed mode, Reynolds number and plate inclination angle. The present time–average film thickness data is compared with the previous experimental and theoretical results showing a good agreement. A new correlation for the average film thickness is suggested. Our results show that the liquid feed mode has a vital influence on the film thickness and that the film thickness increases with Reynolds number and decreased plate inclination angle. The root–mean–square value of the film thickness fluctuations depends non-monotonically on the film Reynolds number. The corresponding mechanisms are analyzed.