Session: 13-02 - Additive Manufacturing

Paper Number: 122409

122409 - Impacts of Material and Machine on the Variation of Additively Manufactured Cooling Channels 

While additive manufacturing (AM) can reduce component development time and create unique internal cooling designs, the AM process also introduces several sources of variability, such as the selection of machine, material, and parameters. Because of these sources, wide variations in a part’s geometrical accuracy and surface roughness levels can occur, especially for small internal cooling features that are difficult to post-process. This study investigates how the selection of machine and material in the AM process influences variations in surface quality and deviations from design intent. Two microchannel cooling geometries were tested: wavy channels and diamond-shaped pin fins. Test coupons were fabricated with five different additive machines and four materials using process parameters recommended by the manufacturers. The as-built geometry was measured non-destructively with computed tomography (CT) scans. To evaluate surface roughness, the coupons were cut-open and examined using optical profilometry. Three distinct roughness profiles on the coupon surfaces were captured including upskin, downskin, and vertically-built features. Results indicated that both material and machine contribute to producing different roughness levels and very different surface morphologies. Compared to the vertically-built coupon walls, the roughness levels on the pin fin surfaces are significantly higher. Along with characterizing the manufacturing of the coupons, cooling performance was investigated by experimentally measuring friction factor and heat transfer. Cooling geometries with higher levels of surface roughness had greater augmentations of friction factor, which was more sensitive to roughness level changes than Nusselt number.

Presenting Author: Abbigail Altland Pennsylvania State University

Presenting Author Biography: Abbigail Altland is a Ph.D. student at the Pennsylvania State University where she conducts research at the Steady Thermal Aero Research Turbine (START) Laboratory. She also received her bachelor’s degree at the Pennsylvania State University during which she worked as a member of the Zhu Group studying day-time radiative cooling. In her current research, she focuses on the development of additively manufactured cooling geometries with applications in gas turbine engines and heat exchangers.

Authors:

Abbigail Y. Altland Pennsylvania State University
Thomas M. Corbett Pennsylvania State University
Karen A. Thole Pennsylvania State University