Session: 15-02 Numerical Studies of Internal Cooling 1

Paper Number: 153570

Numerical and Low-Order Modelling of Double Wall Liner Cooling With Pin-Fins 

Contemporary gas turbine engines have elevated turbine inlet temperatures and consequently combustor chamber and/or reheat chamber wall temperatures rise over the years. Sophisticated cooling schemes has attracted more attention to cope with these high temperature gases. One of the most popular cooling scheme is double-wall cooling, which is an efficient combination of the impingement and effusion cooling techniques. In this scheme, coolant air, at first, impinges on the target plate and then flows through effusion holes before creating a relatively cold film of airflow. Even though this scheme is highly beneficial in terms of cooling, the supporting structure needs integrity. Pressure difference across a double wall structure may rapidly change during a flight mission, creating crushing loads, thus it is beneficial to utilize pin fins between the walls to act as structural reinforcement. As these pins further contribute to cooling by increasing the wetted surface area and raising turbulence intensity, complex configurations start to emerge, which require advanced methods to predict metal temperatures accurately from design standpoint. The dependence of metal temperatures to flow-split is an imperative design choice that needs to be set at early design phases, which shall not consume too much time and design iterations. To overcome this bottleneck, low-order models are needed to estimate metal temperatures fairly accurately and to calculate flow split distribution inside the engine with reasonable fidelity. In this study, a low-order model, based on the article GT2024-129340: Development of a Reduced Order Model for Double Wall Liner Cooling Schemes, is developed for double-wall cooling schemes with embedded pin-fin geometries. In addition to previous study, pin-fin array is added to model as heat loss from the effusion plate. Several test cases with the different blowing ratios are modeled and compared with experimental data to validate the fidelity of the low-order model. Moreover, conjugate heat transfer (CHT) analyses are performed to deduce film cooling trends and information is then fed to the one-dimensional solver for cases, where blowing ratio is beyond correlation ranges. The low-order model and CHT results are compatible with experimental results available in literature for various cases. Current study confirms the applicability of the low-order model for double-wall cooling schemes with pin-fin arrays.

Presenting Author: Zeki Tugberk KARASU TUSAS Engine Industries

Presenting Author Biography: After graduating from mechanical engineering in Dokuz Eylul University in 2019, Karasu started his master's degree in heat transfer and fluid mechanics at Istanbul Technical University. He received the title of master's mechanical engineer in 2022. During his master's degree, he worked as a turbine thermal system design engineer at Tusas Engine Industries (TEI) from 2021 to 2023. During this time, He wrote conference papers on secondary flows in gas turbine engines to be published in the ASME organization. He has been working as an afterburner aerothermal engineer since 2023. In particular he works on innovative technologies for cooling designs and aero designs of afterburner engines.

Authors:

Zeki Tugberk KARASU TUSAS Engine Industries
Fırat KIYICI TUSAS Engine Industries
Erinc Erdem TUSAS Engine Industries