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A conjugate heat transfer analysis methodology has been defined and applied to an Air Force film cooled turbine vane consisting of 648 cooling holes. An unstructured computational mesh was used to model both the fluid and metal sides of the turbine vane. A summary of the numerical methods employed by Code Leo is provided along with a description of the coupling procedure employed between the fluid and heat conduction computations. Numerical simulations were conducted at multiple mesh resolutions to assess accuracy and repeatability. A detailed review is presented for the numerical solution obtained from a fine mesh consisting of 24 million elements (8 million solid, 16 million fluid) covering all 648 film holes. Results showed that cooled air from the film holes formed a protective layer around the airfoil surfaces and endwalls as intended. Low metal temperatures were present not only on the external surfaces exposed to hot gas, but also around the entrances to the film cooling holes. Cooled air was also observed to pile up along the pressure surface at mid-span. Solution convergence was achieved in approximately 15,000 iterations and 100 hours elapsed time on a dual-socket Intel E5504 workstation. The combination of fast turnaround time with accurate metal temperature prediction will enable conjugate heat transfer analysis to be easily incorporated into routine design processes to better address durability goals.Copyright © 2011 by ASME

An experimental approach is used to evaluate a baseline vane airfoil cooling configuration for advanced gas turbine engine application by incorporating arrays of two types of cooling holes at prescribed angles, spacing and sizes into large-scale flat plate specimens. An infrared (IR) imaging system is used to make detailed full-coverage, two-dimensional, steady-state measurements of flat plate surface temperature. A cooled zinc selenide window transparent to IR radiation allows access to thermal measurements, and reference thermocouples embedded in each specimen allow for calibration of the IR temperature readings. The technique is cost effective, repeatable, non-destructive, and it produces abundant results quickly. Here, the technique is used to evaluate overall cooling effectiveness and surface temperature distributions of a nominal modern turbine vane cooling pattern with varying built-in compound and injection cooling flow angles. Tests are performed with and without cooling flow which enters the hot freestream flow at room temperature through the test plate specimen cooling holes over a small range of blowing ratios.