Session: 12-01: Additive Manufacturing in Film Cooling

Paper Number: 152942

Assessment of Additive Manufacturing Repeatability Through Adiabatic Effectiveness Measurements 

Additive Manufacturing has demonstrated significant potential to produce components with complex geometries and small dimensions. This capability has sparked growing interest in recent years, leading to substantial efforts aimed at applying AM methods to enhance film cooling techniques in turbine blade cooling systems. This work investigates the performance and repeatability of film cooling holes fabricated using a Direct Metal Laser Melting (DMLM) technique, focusing on their cooling effectiveness. The proposed hole was developed in the Design-for-Additive-Manufacturing framework, and it aims to obtain a strongly three-dimensional shape with a reduced length compared to traditional holes in order to anticipate the coolant injection over the target surface. PSP measurements were performed for multiple flat plates housing a single row of 11 holes. The adiabatic effectiveness contours downstream of each hole were found to exhibit a strong variability at each tested blowing ratio ranging between 0.25 and 2.00, especially at high BR values. A statistical analysis is performed to quantify the variability of cooling effectiveness, relating thermal performances deviations to manufacturing failure. Furthermore, to understand how deviations in the manufacturing process impact thermal performance, the results of a CT-scan analysis are reported to highlight the main sources of failure. Results show that, while AM enables the production of complex geometry, repeatability remains a challenge, with even a slight variation in the hole geometry strongly jeopardizing cooling performance. The findings highlight the need for rigorous quality control and optimization from hole design to manufacturing process to enhance the reliability of AM-fabricated film cooling solutions in gas turbine applications.

Presenting Author: Niccolo' Castelli University of Florence

Presenting Author Biography: Last year phD candidate at Univeristy of Florence, working on heat transfer phenomena and gas turbine cooling.

Authors:

Niccolo' Castelli University of Florence
Alessio Picchi University of Florence
Bruno Facchini University of Florence
Lorenzo Winchler Baker Hughes
Francesco Morante Baker Hughes