A method to measure vapor concentration of droplet evaporation based on background oriented Schlieren. (April 2021)

• Record Type: Journal Article
• Authors: Zhang, Pu; Xu, Zhikun; Wang, Tianyou; Che, Zhizhao
• Is Part Of: International journal of heat and mass transfer. Volume 168(2021)
• Publication Date: 2021-04
• Subjects: Vapor concentration measurement -- Background oriented Schlieren -- Droplet evaporation -- Droplet impact; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2020.120880
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: A method is proposed to measure the transient concentration field of vapor. The method is based on modified background oriented Schlieren and image processing. Evolution of vapor concentration during impact of volatile droplets is obtained. The vapor distribution differs from diffusion-limited model because of convection. The complex structure of vapor cloud is due to interplay among different factors. Abstract: The direct visualization of vapor distribution and quantitative measurement of vapor concentration plays an important role in studying droplet evaporation. In this study, we propose a method to measure the vapor concentration field based on the modified background oriented Schlieren, inverse Radon transform, high-speed imaging, and image processing. The method is demonstrated for the measurement of the transient concentration field during the impact of volatile droplets on solid surfaces. The results show that the vapor distribution is remarkably different from the diffusion-limited model because of the strong convection. The complex structure of the vapor cloud is the result of the interplay among fluid inertia, fluid evaporation, vapor diffusion, vapor convection, and droplet shape evolution.