Pyo, Yeongmin2025-07-162025-07-162025-07-16http://hdl.handle.net/10393/50663https://doi.org/10.20381/ruor-31248Effusion cooling represents the forefront of cooling technology for gas turbines, particularly within the hot-gas path components. Traditionally, effusion cooling holes are aligned with the combustor axis, resulting in a nominal zero compound angle, which is defined as the angle between the direction of the effusion jet and the mainstream flow in the lateral (transverse) plane. This alignment is based on the assumption that the swirling nature of the main flow does not significantly affect the cooling effectiveness. However, this study challenges this assumption by investigating the directional effects of effusion cooling under the influence of a swirling main flow, particularly focusing on the adiabatic film cooling effectiveness (AFE). The research initially explores the isolated impacts of varying compound angles on AFE, deliberately excluding the influences of changing effusion hole spacing called effusion hole pitch. This approach facilitates a clearer understanding of how non-zero compound angles alone affect AFE. Building on this foundation, the study then examines the combined effects of varying pitch and compound angle, aiming to guide future designs of effusion cooling under swirling flow conditions. To achieve this, a novel effusion cooling design was proposed, featuring varying compound angles of 90, 60, and 30 degrees along the main flow direction. This design was compared against conventional methods with fixed compound angles. Both experimental studies utilized Binary Pressure Sensitive Paint (PSP) and the heat/mass transfer analogy to measure AFE. The results indicate that larger compound angles facilitate quicker initial cooling film build-up, but optimal angles decrease downstream as the cooling film develops. The new effusion cooling design with varying compound angles demonstrated more uniform cooling film coverage and a slight enhancement in AFE compared to traditional designs with fixed angles. These findings suggest that reconsidering the standard alignment and angle of effusion cooling holes, particularly in the context of swirling main flows, can lead to significant improvements in gas turbine cooling efficiency.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/gas turbinefilm coolingeffusion coolingAFEadiabatic film cooling effectivenessPSPpressure sensitive paintcompound anglepitchThesis