Date of Award
1-1-2024
Document Type
Dissertation
Degree Name
Ph.D. in Engineering Science
First Advisor
Taiho Yeom
Second Advisor
Yiwei Han
Third Advisor
Wen Wu
Relational Format
dissertation/thesis
Abstract
In the provided thesis, turbulent statistics over a novel additive surface structure are studied within a fully-developed turbulent channel flow at ReƬ ≈ 380. Experimental data is gathered in a purpose-built 3D-printed wind channel which allows for 2D Particle Image Velocimetry. The Multi Jet Fusion 3D-printed additive structure, consisting of two side walls and a top wall, is analyzed for its flow control capabilities. Potential desirable flow control outputs include localized flow acceleration, deceleration, and vortex generation. The proposed structure is configurable by manipulating the structure’s height and the angle of attack of the side and top walls. Heights of 3, 4, 6, and 7 mm of the structure are investigated, ranging from 12% - 25% of the boundary layer thickness. All observed structure heights fall within the log-law region of the flow. Discussed structures include default, diffuser, and nozzle-type geometries, defined by different angles of attack of the three control walls. Instantaneous and time-averaged ensemble data are collected. Manipulations to velocity, Reynolds stresses, and turbulence kinetic energy are discussed. Results show that for 6 mm and 7 mm height surface structures, a default structure geometry produces localized near-wall flow acceleration without significantly perturbing free-stream flow. Further, nozzle geometries produce slight free-stream flow deceleration while diffuser geometries produce slight free-stream flow acceleration. Diffuser geometries produce three downstream regions of noteworthy energy production due to vortex generation on the trailing edge of the top surface, the internal top wall, and the channel wall. Nozzle geometries produce a large region of intense energy production and shear due to vortex generation over the structure’s top wall and the top wall’s trailing edge. Additionally, certain 6 mm height structure geometries impact turbulence statistics more than 7 mm height structures. Recommendations are made for future study.
Recommended Citation
Moore, Tyler Jesse, "Particle Image Velocimetry Investigation of a Novel Structure within a Turbulent Boundary Layer" (2024). Electronic Theses and Dissertations. 2845.
https://egrove.olemiss.edu/etd/2845