Session: 13-05: Influence of manufacturing techniques on heat transfer

Paper Number: 151422

Effect of Morphological Variations in TPMS Lattice Structures on Transpiration Cooling 

The development of advanced cooling technologies for modern aero engines has become essential to protect critical gas turbine components, such as the combustion chamber, from increasingly extreme thermal environments and to extend their operational lifespan. Among the various cooling techniques, transpiration cooling stands out due to its notable merits, including efficient heat exchange through the extended wetted surface area between the porous solid structure and the cooling fluid, as well as the formation of an effective and uniform cooling gas film on the wall surface without lift-off. However, the performance of transpiration cooling relies on the precise control of pore size to ensure uniform film cooling distribution across the entire surface and to prevent the formation of localized hot spots. Recent advancements in additive manufacturing (AM), commonly known as 3D printing technology, have enabled the fabrication of lattice-based deterministic porous media with precisely controlled pore sizes and distributions. Among the various lattice structures used in transpiration cooling systems, Triply Periodic Minimal Surfaces (TPMS) have drawn significant attention due to their high performance and periodic characteristics, which can be precisely controlled. The potential of transpiration cooling using this family of lattice geometries has been demonstrated in previous studies. However, optimizing transpiration cooling using TPMS lattice-based porous media in real gas turbine components remains challenging due to the complex geometric features of these parts: their surface curvature and uneven thickness lead to variations in texture and void patterns on the porous media surface. These variations significantly affect the performance of film cooling. This study investigates experimentally how film cooling effectiveness is affected by the different porous media surface void patterns that results from cutting cross-sections through of the TPMS lattice at various heights within its unit cell. The goal is to understand how these cross-sectional height variations affect transpiration cooling performance and to identify TPMS geometries that are ideally least sensitive to such variations. Three types of TPMS structures, namely Diamond, Koch, and Gyroid, were used to evaluate film cooling performance based on surface patterns. The Pressure Sensitive Paint (PSP) technique was employed to provide high-resolution data on film cooling effectiveness.

Presenting Author: Juchan Son University of Ottawa

Presenting Author Biography: Juchan Son is a Ph.D. student in Mechanical Engineering at the University of Ottawa and a visiting researcher at the National Research Council Canada (NRC). His research focuses on optimizing transpiration cooling through porous media with lattice structures using additive manufacturing techniques. Juchan’s work aims to improve thermal management systems by exploring innovative designs in heat transfer and fluid dynamics.

Authors:

Juchan Son University of Ottawa
Patrick Richer University of Ottawa
Bertrand Jodoin University of Ottawa
Zekai Hong National Research Council of Canada