Liquid Film Thickness Measurement: A Critical Review

Abstract

There is a growing demand for high-performance cooling. Two-phase flow through microchannels involving phase change (thin-film evaporation) is one of the prospective techniques for high-performance cooling. Liquid film thickness is a prominent parameter in the study of thin-film evaporation. Measurement of film thickness in macro-, mini-, and microscale channels has drawn many researchers’ attention from the past few decades. Many numerical techniques, analytical models, and experimental methods have been proposed in this regard. In the present study, an attempt is made to present a comprehensive literature review of the methods used so far for the measurement of liquid film thickness. Further, image processing technique is demonstrated as a potential candidate for the measurement of liquid film thickness.