Date of Award
2026
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Aerospace Systems Engineering
Committee Chair
Phillip Ligrani
Committee Member
Guangsheng Zhang
Committee Member
Haiyang Hu
Research Advisor
Phillip Ligrani
Subject(s)
Alloys--Mechanical properties, Additive manufacturing, Surface roughness
Abstract
Considered are heat transfer and friction factor characteristics of two different millimeter-scale passages within HR-1 alloy material. The associated test components are additively manufactured using laser directed energy deposition. The surfaces of the first passage are the result of no post-processing after production, and the surfaces of the other passage are due to abrasive flow machining. As a result of these different surface processing procedures, different texture and roughness are present on the inside surfaces of the two passages. An experimental apparatus consisting of a set of plenums, etched-foil heaters, a high-pressure regulated K-bottle, and other components is used. Working fluids are carbon dioxide gas and helium gas. A constant heat flux boundary condition is employed to determine the heat transfer coefficients and Nusselt numbers for a range of flow conditions, and the pressure drop experienced by the flow within the passage is normalized to obtain the Darcy friction factor. Observed gas characteristics are associated with laminar, transitional, and low Reynolds number turbulent flow regimes. Heat transfer coefficients and friction factors increase significantly with passage Reynolds number. Heat transfer coefficients, Nusselt numbers, and Darcy friction factors are generally higher for the unprocessed passage, relative to the passage with abrasive flow machining, when compared at the same Reynolds number.
Recommended Citation
Porthouse, Connor, "Heat transfer and friction factor characteristics of millimeter-scale channels within additively manufactured HR-1 alloy material" (2026). Theses. 828.
https://louis.uah.edu/uah-theses/828