Demand for more power from a gas turbine causes rotor inlet temperature to increase and in order to restrict the metal temperature in hot gas path components within a safe working limit, a better cooling system must be employed. This paper focuses on evaluating the performance of a film cooling hole in engine like conditions. Lab-scale experiments conducted prior to this study have established that tripod holes provide higher effectiveness compared to cylindrical and shaped holes while consuming only half the coolant. In spite of showing potential, it still has to yield superior cooling at engine like conditions. The high temperature test rig facility at NETL can raise the mainstream gas temperature as high as 1175 °C. Coolant temperature is adjusted to study film cooling performance at density ratio 2.8. This study presents results of baseline coupon testing. Metal coupons are made of Haynes230 alloy and are fabricated with cylindrical holes. Surface temperature is recorded using an IR thermographic camera which was calibrated using thermocouples, for different blowing ratios (0.5–2.0). Alongside experiment, a numerical model was also developed in an attempt to provide additional insight on the distribution of surface temperature and overall effectiveness downstream of cooling hole. It was observed that film cooling is effective at M=2.0 and 1.5 and this was associated with high inlet turbulence and swirling velocities disrupting the film cooling performance at lower blowing ratios. CFD predictions seemed to match better at M 1.0 but were found to deviate considerably at other blowing ratios.
