Evaluation of the geometrical parameters of collector mesh on the fog collection efficiency

Fog collectors have gained increasing attention as an efficient solution to overcome the water scarcity concerns in arid and semiarid environments. Besides the rapid advances made in various collector designs, the role of geometrical characteristics of the fog collector meshes is not fully understood. Therefore, the main objective of the present research is to address this issue and investigate the effects of textile features on the efficiency of conventional meshes which has not been discussed in previous works. The collection efficiencies of various conventional structures (plain-woven, plain-knitted, and 3-D spacer) with different characteristics (fiber diameter, fiber spacing, fiber arrangement, shading coefficient, and test direction) were investigated using a custom-made fog collecting device. The weight of collected water over time and the onset time were measured to assess the performance of different samples. Moreover, a simple simulation of a plain-woven structure was developed using Computational Fluid Dynamics (CFD) to perform further analysis. The results revealed that in the woven structure, the collection efficiency was improved by changing the shading coefficient to an optimum value and simultaneous decreasing fiber diameter. In the spacer fabrics, the position and arrangement of the spacer fibers posed considerable effects on the collection efficiency. 3-D spacer meshes showed highest value of collection efficiencies and onset time in comparison to the other examined meshes. The results of simulation of woven structures were also validated by comparing computed and measured collection efficiencies.