Conjugate heat transfer analysis of a rotor blade with coolant channels

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.