Thermal analysis of droplet flow: Numerical, analytical and experimental investigations

This article reports the thermal behavior analysis of droplet flow for a scenario in which the hydrodynamic and thermal effects are coupled in a cylindrical miniaturized channel; this analysis was performed by comparing numerical, analytical and experimental results. The 3D numerical modeling of the droplet flow was performed using THETIS, a multi-fluid Navier-Stokes solver. A 1D analytical model in Lagrangian space based on a thin-fin thermal approximation was developed. Infrared thermography measurements of droplet flows were used to experimentally determine the temperature fields inside droplets, and these results were compared with those obtained from the simulations and the analytical approach. The originality of this work is the choice of a particular thermal scene to mimic a chemical situation in order to improve understanding and to illustrate the predominant exchanges by model simplification. Furthermore, the results of this study are important for understanding the heat transfer occurring inside droplets for lab-on-chip applications.