Abstract Novel turbine blade cooling geometries have been assessed using computational methods, simplified flat-plate geometries, or large-scale wind tunnel models at low technology readiness levels. Even when cooling geometries have demonstrated a beneficial heat transfer augmentation in simplified test environments, additional challenges arise when these features are integrated into real turbine hardware. In particular, integrated features are subject to manufacturing-driven limitations. This study integrated cooling designs, previously reported in the open literature, into a true-scale turbine blade to assess the overall cooling performance of each geometry. Four unique blade sets were manufactured to evaluate three cooling hole geometries (cylindrical, 7-7-7 diffused, and tripod anti-vortex); additional comparisons were also made between trailing edge designs incorporating a densely-spaced diamond pedestal array relative to a baseline impingement slot-fed design. Both the tripod cooling holes and the densely-spaced pedestals are cooling technologies that represent aggressive designs and also manufacturing challenges. All four sets of blade designs were tested concurrently using a rainbow wheel configuration in the Steady Thermal Aero Research Turbine (START) Lab. Blade surface temperatures were measured using thermal imaging methods while computed tomography scans provided insight to how manufacturing variations impacted the mass flow rate through each blade. The anti-vortex tripod holes offer the most lateral spreading when compared with the baseline 7-7-7 hole design. The diamond pedestal trailing edge section showed similar overall effectiveness to the baseline design for a lower mass flow rate to achieve similar blade temperatures.
Gailey et al. (Wed,) studied this question.