Grooves spacing govern water retention during condensation

2025/09/16 by Nicolas Vandewalle, Leonard, Matteo, Vandewalle, Nicolas · 1 citation
Energy · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Solar-Powered Water Purification Methods

paper · pdf · doi:10.48550/arxiv.2509.12736

openalex publication_date 2025/09/16 · openalex created_date 2025/10/18 · openalex updated_date 2026/07/28

Abstract

Condensation on vertical surfaces leads to fluid retention, which limits the efficiency of applications ranging from heat exchangers to atmospheric water harvesters. A common strategy is to structure the surface with grooves, yet whether grooves help drainage or worsen retention remains unclear. Here we use a high-throughput condensation setup to quantify retention on substrates patterned with parallel vertical grooves of fixed geometry (d/w=1) while varying the spacing s. We uncover two opposite regimes separated by the droplet detachment radius R_d. For large spacings (s>R_d), droplets grow and slide under gravity while grooves, acting as passive reservoirs, increase retention. For small spacings (s

Citations

• Droplets sliding on single and multiple vertical fibers
• Wetting morphologies and their transitions in grooved substrates
• Purity of the sacred lotus, or escape from contamination in biological surfaces

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• Stretching water between two grooves

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