Onset time of fog collection

Area of Science:

• Environmental science and engineering
• Fluid dynamics
• Materials science

Background:

• Fog collection is vital for addressing global water scarcity and industrial water recapture.
• Existing research focuses on fog collection rates, neglecting the critical initial 'onset time'.
• Longer onset times can lead to clogging and reduced collection efficiency, necessitating further study.

Purpose of the Study:

• To systematically investigate the factors influencing fog collection onset time.
• To understand the relationship between onset time, fog capture, and droplet-surface interactions.
• To develop a predictive model for optimizing fog collector performance.

Main Methods:

• Experimental study using individual vertical wires with varying surface wettabilities and diameters.
• Controlled wind speeds to simulate different fog-laden flow conditions.
• Analysis of droplet growth, capture, and transport dynamics.

Main Results:

• Derived a scaling law correlating onset time with fog capture and droplet-surface retention force.
• Onset time is inversely related to the rate of fog capture.
• Onset time decreases with reduced droplet-surface retention force.

Conclusions:

• Introduces onset time as a key parameter in fog collection efficiency evaluation.
• Provides fundamental insights into the interplay of aerodynamics and interfacial phenomena.
• Offers guidance for designing more effective fog collectors and mist eliminators.