Flow and heat transfer of various internal cooling technologies for rotating blades: A review on recent twenty-years progress of experimental studies

Internal cooling technologies are essential for ensuring the reliable operation of gas turbine blades under extreme high-temperature environments. For rotating blades, Coriolis and rotational buoyancy effects critically alter the flow and heat transfer characteristics within internal cooling channels, which cannot be neglected. In this paper, a comparative analysis is first conducted on the advantages and limitations of measurement techniques including thermocouple-copper plate method, naphthalene sublimation methods, steady-state/transient liquid crystal thermography (LCT/TLCT), infrared thermography (IRT), laser doppler velocimetry (LDV), particle image velocimetry (PIV), and hot-wire anemometry (HWA), with focused discussions on the technical specifications of representative rotating test facilities. Subsequently, experimental data from multi-pass serpentine channels, pin–fin arrays channels, and impingement cooling channels are synthesized to elucidate the influence mechanisms of Coriolis and buoyancy effects on flow and heat transfer within the channels. Finally, recommendations are proposed for future experimental research. This literature review serves as a valuable reference for the design of rotating test facilities and the optimization of internal cooling structures in turbine rotor blades. This paper systematically reviews advancements in experimental studies on rotating internal cooling from the past two decades, while also referencing earlier and seminal works to provide foundational insights.