Drops impacting inclined fibers.

Area of Science:

• Fluid dynamics
• Materials science
• Surface science

Background:

• Fiber mats are widely used for liquid drop capture in applications like filtration and fog harvesting.
• Optimizing capture efficiency, especially for drops larger than fiber diameters, is crucial for filter performance.
• Current fiber filter designs often exhibit high permeability, limiting their effectiveness with larger droplets.

Purpose of the Study:

• To investigate the effect of fiber orientation on liquid drop capture efficiency.
• To determine if tilting fibers can enhance the performance of fiber-based liquid capture systems.
• To analyze the impact of fiber tilt on droplet capture velocity and retained liquid volume.

Main Methods:

• Experimental investigation of liquid drop impact on fiber mats.
• Systematic variation of fiber mat tilt angle relative to droplet trajectory.
• High-speed imaging and analysis of droplet-fiber interactions.

Main Results:

• Fiber tilting dramatically increases the critical capture velocity (V*) below which drops are fully captured.
• Optimized fiber tilt angles were found to significantly enhance capture efficiency.
• Maximization of liquid volume retained on the fiber was observed at specific tilt angles for impacts exceeding V*.

Conclusions:

• Tilting fiber mats is a highly effective strategy for improving liquid drop capture.
• This approach enhances both the capture threshold velocity and the liquid retention capacity of fiber filters.
• The findings offer a simple yet powerful method to optimize fiber-based liquid collection technologies.