A Novel and More Efficient Oscillating Foil for Wave-Driven Unmanned Surface Vehicles

Area of Science:

• Marine engineering
• Oceanic engineering
• Robotics

Background:

• Wave-driven unmanned surface vehicles (WUSVs) utilize oscillating foils for wave energy conversion, but often exhibit slow speeds.
• Improving WUSV speed is crucial for enhanced maneuverability and efficient mission completion in oceanic environments.

Purpose of the Study:

• To propose and validate a novel method for enhancing the thrust force of oscillating foils.
• To increase the operational speed of WUSVs through improved foil design.

Main Methods:

• Employing asymmetric cross-section shapes and asymmetric oscillating motions for oscillating foils.
• Utilizing computational fluid dynamics (CFD) simulations for theoretical validation.
• Conducting pool experiments and sea trials to verify thrust and speed enhancements.

Main Results:

• The asymmetric foil design demonstrated a propulsive force enhancement of at least 13.75%.
• A corresponding speed increase of at least 7.6% for WUSVs was achieved and verified across simulations and sea experiments.
• The modifications required are low-cost, involving changes to traditional rigid symmetric foils.

Conclusions:

• Asymmetric oscillating foils offer a cost-effective solution to significantly improve WUSV performance.
• This method enhances thrust, leading to increased WUSV speed and better maneuverability for ocean missions.