As gas turbine engines are driven to be more efficient, quiet, and to produce less pollutant the turbine inlet temperature has a tendency to be driven upwards. The life of a turbine engine component decreases dramatically as the metal temperature increases. Because film cooling of high-pressure turbine airfoils has become common practice, improving the ability to predict film-cooling effectiveness is a critical problem of interest. Finding better, more efficient ways to use the cooling air is far preferable to using more of it. However, even if a given cooling-hole configuration proves to be effective in a flat-plate environment (which is the test article of interest in this thesis), it may not be effective on a turbine blade that is exposed to dynamic conditions that cannot be easily replicated.
The goal of the experiment reported here is to measure the film effectiveness for a blowing ratio, temperature ratio and free stream Mach number, all similar to those experienced by the pressure surface of a rotating blade turbine blade with the same cooling-hole configuration, but for the flat-plate test article noted above. The cooling gas flow will be initiated earlier than the main flow to allow for proper setup of the cooling flow. This data will be used as a comparison to simulation results obtained using the CFD code Fine TURBO. It is shown in this work that the cooling-gas supply system interaction with the external gas supply associated with the blowdown facility process is not simple, and the current model used to design the experiment is not as good as it could have been. The effect of cooling was observed and the data closely resembled the simulations done using the CFD code Fine TURBO. Unfortunately, due to problems with the double-sided Kapton heat-flux gauges, heat flux data was not obtained in the immediate vicinity of the cooling holes. Solutions to the problems encountered in this experiment are relatively straightforward and are presented.