Review of Optical Techniques for Studying Interfacial Dynamics in Multiphase Flows and Phase Change Heat Transfer

Abstract

Abstract Optical techniques are widely used in a variety of applications that are related to biology, physics, and material science due to their inherent advantages (e.g., non-intrusive, fast data processing, and high resolution). Even though optical techniques were initially developed in 19th century, advanced optical techniques have recently been used in multiphase flows and phase change heat transfer studies (e.g., boiling, evaporation, and condensation). In this review, the optical techniques that are used in micro/nanoscale heat transfer, (e.g., phase change, dropwise condensation and evaporation and thin film measurements), as well as characterization of profiles (e.g., for micro-droplets) are explored. The scope of optical techniques reviewed in this study is limited to surface plasmon resonance, fringe equal chromatic order interferometry, ultrathin film interferometry, total internal reflection (A-TIR) and shadowgraph techniques. The efficacy and advantages of optical techniques were explored for various applications. These optical techniques can be leveraged for illuminating the complicated physics governing different types of multi-phase flows (e.g. during dropwise condensation). The potential deployment of these novel optical techniques in various types of multi-phase flow configurations are also explored in this study (e.g., thin-film evaporation, boiling, etc.).