When Textures Trim Drag: Micro-Structures for Adaptive Drag Reduction and Flow Authority

Author

Miguel Angel Olvera, The University of Texas Rio Grande Valley

Date of Award

12-1-2025

Document Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Mechanical Engineering

First Advisor

Isaac Choutapalli

Second Advisor

Robert Freeman

Third Advisor

Arturo Fuentes

Abstract

Turbulent boundary layers are a major source of drag and performance loss. This thesis investigates Triangular Porous Texturing (TPT), apex-forward microstructures with optional bleed channels, as a passive concept for simultaneously reducing skin friction and strengthening boundary layer momentum near separation. Low-speed wind tunnel tests are conducted over tripped turbulent boundary layers on flat plates with three surfaces: a smooth baseline, a solid-crest TPT array isolating the knife-edge “slip-cut” effect, and a porous-bleed TPT array whose paired micro-channels vent a small fraction of the free stream. Time-resolved PIV provides wall-normal velocity fields; skin friction is inferred from near-wall shear, and the Fukagata–Iwamoto–Kasagi identity links local Reynolds-shear changes to drag. Solid TPT reduces skin friction by nearly 20%, while porous TPT slightly increases mean drag but boosts log-layer momentum flux, establishing TPT as a dual-mode, cruise-to-maneuver surface.

Comments

Copyright 2025 Miguel A. Olvera. All Rights Reserved. https://proquest.com/docview/3292588747

Recommended Citation

Olvera, M. A. (2025). When Textures Trim Drag: Micro-Structures for Adaptive Drag Reduction and Flow Authority [Master's thesis, The University of Texas Rio Grande Valley]. ScholarWorks @ UTRGV. https://scholarworks.utrgv.edu/etd/1839