<p>In the turbine cooling literature, a wide variety of film cooling shaped hole configurations are described.&nbsp; Although it is clear that shaped holes significantly outperform cylindrical holes, providing higher levels film effectiveness over a greater range of blowing ratios, there have been no studies in which am optimum shaped hole configuration has been systematically determined. &nbsp;In this study, a combined computational and experimental process was used to determine the optimum lateral and forward expansion angles for a film cooling hole with a diffusing expansion at the exit of the hole.&nbsp;&nbsp; RANS simulations were used to quickly screen a large number of potential geometries for improved performance and then the actual performances for selected geometries were experimentally validated. Results from these experimental validations showed 40% increases in film effectiveness compared to a baseline 7-7-7 shaped hole. The trends seen within the CFD data set were also validated experimentally to show that diffuser performance is only a function of AR, VR, and (t/P) and not a function of forward or lateral expansion angle. These methods are inherently general and easily applied to a wide range of film cooling shapes and cooling configurations with the only restrictions being the limitations of RANS which is unable to predict the actual surface temperature of a component but is entirely capable of predicting trends in performance. The ability to screen a large number of geometry changes computationally before validating a small subset of holes experimentally allows the exploration of far more complex design spaces available in AM without requiring significantly increased experimental testing capacity.</p>

Parametric Optimization of Film Cooling Hole Geometry

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2021/volume/84898

Turbo Expo 2021

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.