On the aerodynamic fog collection efficiency of fog water collectors via three-dimensional numerical simulations

Carvajal, Danilo; Silva-Llanca, Luis; Larraguibel, Dante; González, Bastián

Keywords: computational fluid dynamics, fog water collection, Aerodynamic collection efficiency, Turbulence numerical simulations


Fog water collection gained interest in recent years as an emerging solution for water scarcity in arid and semi-arid areas. During a fog event, a porous mesh screen of plastic polymer retains the water through droplet impaction, where the droplets coalesce and trickle into a gutter for collection. This type of collecting system has existed since the 1960s; however, a substantial lack of understanding remains as to the aerodynamics that dominates the collection phenomena. The Aerodynamic Collection Efficiency (ηa) is the determining factor in the overall performance of such systems. This paper aims to further the fundamental knowledge on the aerodynamic behavior during fog collection. For this, a three-dimensional computational fluid dynamics model was developed, where the collector's mesh was modeled as a porous medium, which simulates a conventional two-dimensional double layer mesh. A parametric study was carried out varying the mesh's geometric characteristics (flat and concave), mesh-to-ground distance, and wind speed. The effect of wind speed on aerodynamic collection efficiency is mainly determined by the relative relationship between the viscous and inertial pressure drop in the porous medium. A greater curvature reduces the mesh's airflow impedance, leading to a significant improvement of the aerodynamic collection efficiency. Within the parameter range of our study, we found a maximum aerodynamic collection efficiency of 35% for the largest curvature (1.1 m), the highest mesh-to-ground distance (2 m), and the maximum wind speed (5 to 7 m s−1).

Más información

Título de la Revista: ATMOSPHERIC RESEARCH
Editorial: Elsevier Science Inc.
Fecha de publicación: 2020
Idioma: Inglés
URL: https://doi.org/10.1016/j.atmosres.2020.105123

DOI: 10.1016/j.atmosres.2020.105123

Notas: ISI, Scopus