Date of Completion

Summer 8-31-2020

Thesis Advisor(s)

Leslie Shor

Honors Major

Chemical Engineering

Disciplines

Transport Phenomena

Abstract

Retention and evaporation of water have important implications in many natural and industrial settings. Here we focus on the effect of solute components (salts) as well as system geometry on evaporation rate of water. The study of multicomponent solutions with phase changes is challenging topic because of the complex and inter-connected physical phenomena that govern its dynamics. In the present work we review the theory of water evaporation and simulate evaporation of water as a function of composition and geometry for both droplets and bulk-scale (slit-like) systems. For droplets, we studied levitated droplets and droplets over hydrophobic and hydrophilic surfaces. The Maxwell approach, the š¯‘‘! law, the Constant Contact Area mode (CCR) and Constant Contact Angle mode (CCA), the Hertz-Knudsen (HK) relation, and Fickā€™s law of diffusion were examined. Here, we find the droplet radius influences the solutionā€™s evaporation time for both water and aqueous salt solutions at the droplet level. Larger droplets exhibit longer drying times, and the presence of salt also increases drying time. Evaporation was modeled at the bulk scale and compared to published results of drying times for aqueous solutions. We find there is a 13% discrepancy between the measured and simulated results, likely accounting for external mass transport limitations in the experimental system.

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