Diffuser holes are used extensively for film cooling because they dramatically improve film-cooling effectiveness relative to round holes, but there is concern that the drawbacks of a compound angle (CA) may reduce the beneficial effects. This work uses Magnetic Resonance Velocimetry (MRV) to obtain the 3D, 3-component mean velocity field for a shaped hole with a pitch angle of 30 degrees, blowing ratio of unity, and compound angles of 10 and 20 degrees. The data are compared to a previous MRV measurement of an identical hole with zero skew angle. In the 0 and 20 degree cases, a separation bubble is observed on the downstream wall of the diffuser. Streamtubes emanating from the diffuser exit show the asymmetry of the flow as the jet is accelerated to align with the mainstream flow. Streamtube analysis shows evidence of competing effects of CA on film cooling performance: a wider streamtube footprint may increase coverage while a decrease in streamtube thickness may make coverage more susceptible to turbulent mixing. Analysis of the jet trajectory, defined as the streamtube centroid, shows that the realignment of the jet fluid with the freestream direction occurs in the region of the diffuser exit. Although significant qualitative changes in film cooling performance are not expected, some ingestion of mainstream flow may occur due to vortices present in the diffuser below the plane of the blade surface.
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