Evaporation of sessile drops on a heated superhydrophobic substrate

Fuente: arXiv
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Main Authors: Kavuri, Sivanandan, Sharma, Chander Shekhar, Karapetsas, George, Sahu, Kirti Chandra
Format: Preprint
Published: 2025
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author Kavuri, Sivanandan
Sharma, Chander Shekhar
Karapetsas, George
Sahu, Kirti Chandra
author_facet Kavuri, Sivanandan
Sharma, Chander Shekhar
Karapetsas, George
Sahu, Kirti Chandra
contents We experimentally investigate the evaporation dynamics of sessile water droplets on a micro-nano textured superhydrophobic aluminum substrate at various temperatures using shadowgraphy imaging. By comparing the evaporation behavior of two droplets placed side-by-side with that of an isolated droplet, we find that droplets in the two-drop system evaporate more slowly due to the vapor shielding effect, which increases vapor concentration between the droplets. This leads to asymmetric evaporation and longer lifetimes, particularly at room temperature compared to higher temperatures. At room temperature, the isolated droplet primarily follows a constant contact angle (CCA) mode, with occasional stick-slip events. The two-drop system predominantly exhibits CCA mode for most of its lifetime, with mixed-mode evaporation and some stick-slip behavior. At elevated temperatures, the isolated droplet maintains a nearly constant contact angle for the first half of its lifetime, transitioning to a mixed evaporation mode with occasional stick-slip events. In contrast, the two-drop system follows a mixed evaporation mode throughout, with occasional stick-slip behavior. Furthermore, a comprehensive theoretical model that accounts for diffusion, evaporative cooling, and convection accurately captures the evaporation dynamics of sessile droplets on a superhydrophobic substrate in both isolated and paired configurations at elevated substrate temperatures. In contrast, a diffusion-based model alone adequately describes the evaporation behaviour at room temperature.
format Preprint
id arxiv_https___arxiv_org_abs_2507_00774
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Evaporation of sessile drops on a heated superhydrophobic substrate
Kavuri, Sivanandan
Sharma, Chander Shekhar
Karapetsas, George
Sahu, Kirti Chandra
Fluid Dynamics
We experimentally investigate the evaporation dynamics of sessile water droplets on a micro-nano textured superhydrophobic aluminum substrate at various temperatures using shadowgraphy imaging. By comparing the evaporation behavior of two droplets placed side-by-side with that of an isolated droplet, we find that droplets in the two-drop system evaporate more slowly due to the vapor shielding effect, which increases vapor concentration between the droplets. This leads to asymmetric evaporation and longer lifetimes, particularly at room temperature compared to higher temperatures. At room temperature, the isolated droplet primarily follows a constant contact angle (CCA) mode, with occasional stick-slip events. The two-drop system predominantly exhibits CCA mode for most of its lifetime, with mixed-mode evaporation and some stick-slip behavior. At elevated temperatures, the isolated droplet maintains a nearly constant contact angle for the first half of its lifetime, transitioning to a mixed evaporation mode with occasional stick-slip events. In contrast, the two-drop system follows a mixed evaporation mode throughout, with occasional stick-slip behavior. Furthermore, a comprehensive theoretical model that accounts for diffusion, evaporative cooling, and convection accurately captures the evaporation dynamics of sessile droplets on a superhydrophobic substrate in both isolated and paired configurations at elevated substrate temperatures. In contrast, a diffusion-based model alone adequately describes the evaporation behaviour at room temperature.
title Evaporation of sessile drops on a heated superhydrophobic substrate
topic Fluid Dynamics
url https://arxiv.org/abs/2507.00774