Conjugate heat transfer analysis of a rotor blade with coolant channels

Abstract

The present study deals with the conjugate heat transfer analysis of a cooled high-pressure turbine rotor blade consisting of eight cooling channels. Computational investigations are performed in a five-bladed cascade to determine characteristics of flow and heat transfer at different values of mainstream and coolant flow rate. Surface temperature measurements using infrared thermography are performed for validating the computational fluid dynamics results. The results show nonuniform variation of surface effectiveness: (a) higher average surface temperature on the pressure side than on the suction side, (b) peak surface temperature at the pressure side trailing edge region, (c) lowest temperature at midspan region of both pressure and suction sides, (d) intermediate values of temperature on the leading edge, and (e) these temperature patterns vary with the changes in mainstream Reynolds number and coolant flow rates, signifying the importance of carrying out conjugate heat transfer analysis. This study also emphasizes the importance of considering realistic coolant channel geometry over the idealized, an illustration showed that the maximum Nusselt number may vary up to 200% due to idealization.

Mini-channel embedded film cooled flat plate: conjugate heat transfer analysis and enhancement study

“…External cooling, in which coolant ejected from a film hole develops a protecting cover of coolant near the outer wall and protects the blade material. Internal cooling, such as impingement and convection cooling (Won et al, 2004;Luo et al, 2016;Singh et al, 2021aSingh et al, , 2021bQiu et al, 2021;Yan et al, 2022), is the main blade cooling technique. Turbulators are also used in the cooling passage to improve cooling performance.…”

“…The study also involved varying Biot numbers (ranging from 0.013 to 3.162) to analyze their impact on the overall cooling performance. All simulations were conducted under normal temperature ranges (not actual turbine conditions) and low speeds to demonstrate conceptual designs that can be further validated through experiments (Jung et al , 2017; Nowak and Wróblewski, 2011; Panda and Prasad, 2014; Wang et al , 2015; Kazemi Kelishami and Lakzian, 2017; Fawzy et al , 2020; Singh et al , 2021a, 2021b). The temperature ratio considered for the simulations ranged from 0.67 to 0.95 (Jung et al , 2017; Jaiswal et al , 2021).…”