Unlocking the Coupled Hydro-Acoustic Mechanisms and Benefits of Bioinspired Micropillars
Abstract
Efficient propulsion for cross-domain or hybrid aerial underwater vehicles (HAUVs) is highly desirable but is indeed a big challenge due to the order-of-magnitude difference in viscous force and added mass phenomena that exist between operating in sea and air. This project seeks to gain new understanding of the momentum and energy transfer modes of bioinspired micropillar coatings on underwater propeller blades that can be used for a novel amphibious propulsion method with low-frequency Flapping Blades (FB) for underwater use (akin to fish-like locomotion), and high-frequency Rotating Blades (RB) for aerial use (akin to drone propellers). The blades contain an elliptical planform shape and are inspired from the ÔsamaraÕ maple seed which contains superior aerodynamic characteristics that allow these seeds to travel large distances compared to others. The FB and RB methods will be tested with a micropillar surface which is the subject of an investigation for drag reduction in quasi-steady two-dimensional flow and ongoing investigation in three-dimensional vortex dominated rotor flows. A major unique aspect of the project is the proposed water tunnel/tank flow and acoustic experiments at the Naval Undersea Warfare Center, Division Newport (NUWC DIV NPT), where PI Maldonado was recently a Summer faculty research fellow (June-August, 2022) working with lab mentor, Dr. Christin Murphy who is the Branch Head for signal processing an algorithm development (Code 1513). The main goal of the 10-week research visit was to conduct preliminary water tunnel tests and collect power and thrust measurements produced by an underwater propeller thruster with passive micropillar structures on the propeller blade surfaces. The preliminary results have shown up to ~10% electric power reduction (which is directly related to propeller torque and drag reduction) and is dependent on the pillar height and water inflow velocity.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 24, 2023
- Source ID
- W911NF2310228
Entities
People
- Victor Maldonado
Organizations
- Army Contracting Command
- Office of the Secretary of Defense
- Texas Tech University