Mitigating cavitation erosion using biomimetic gas-entrapping microtextured surfaces (GEMS)

Area of Science:

• Fluid dynamics
• Materials science
• Biomimetics

Background:

• Cavitation, the formation and collapse of vapor bubbles, causes significant damage to machinery like ship propellers and pumps.
• Existing surface treatments, including coatings and hardening, are often ineffective against persistent cavitation erosion.
• High-speed jets formed during bubble collapse focus energy onto solid surfaces, leading to material degradation and operational downtime.

Purpose of the Study:

• To develop and investigate novel biomimetic gas-entrapping microtextured surfaces (GEMS) for mitigating cavitation erosion.
• To explore the mechanism by which entrapped air prevents cavitation damage.
• To assess the potential of GEMS as an inexpensive and environmentally friendly solution.

Main Methods:

• Fabrication of biomimetic gas-entrapping microtextured surfaces (GEMS).
• Experimental testing of GEMS in high-speed flow conditions to evaluate cavitation resistance.
• Theoretical analysis using potential flow theory for a multi-bubble system to understand the underlying physics.

Main Results:

• GEMS robustly entrap air within their microcavities, irrespective of the substrate's wetting properties.
• Entrapped air effectively repels incoming cavitation bubbles, preventing direct contact and subsequent damage to the surface.
• The study provides mechanistic insights into the bubble-repelling phenomenon through fluid dynamics modeling.

Conclusions:

• Biomimetic gas-entrapping microtextured surfaces (GEMS) offer a robust and effective method for preventing cavitation erosion.
• The air-entrapment mechanism provides a novel approach to protect machinery operating in high-speed flow environments.
• GEMS represent a promising, cost-effective, and eco-friendly solution for mitigating damage caused by cavitation.