Vapor-shielding effect and evaporation characteristics of multiple droplets

Document Type

Article

Publication Date

5-2023

Department

Department of Mechanical Engineering-Engineering Mechanics

Abstract

This study investigates the vapor shielding effect and evaporation characteristics of multiple droplets, considering the droplet-to-droplet distance, and suggests an evaporation rate model that considers vapor accumulation. Particle image velocimetry (PIV) is applied to visualize the internal flow of the evaporating droplets. The vapor distribution and local evaporation flux are analyzed through numerical simulations under quasi-steady-state assumptions. The results show that droplet adjacency delays the lifetime of the multiple droplets, compared to the single-droplet evaporation time, due to the vapor-shielding effect. Further, the water vapor of a single droplet reveals axisymmetric distributions, while the multiple droplets show vapor accumulation at the adjacent region. The evaporation flux is also dramatically suppressed in the adjacent region in the case of multiple droplets. Based on these findings, a new evaporation rate model is suggested in this research; the model considers the non-uniform distribution of vapor that rises due to the evaporation of adjacent droplets. This model can accurately estimate the evaporation rate for both center and side droplets.

Publication Title

International Communications in Heat and Mass Transfer

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