Heat Transfer Measurements Using Thin Film Gauges and Infrared Thermography on a Film Cooled Transonic Vane
This work presents a comparison of thin film gauge (TFG) and infrared (IR) thermography measurement techniques to simultaneously determine heat transfer coefficient and film cooling effectiveness. The first comparison was with an uncooled vane where heat transfer coefficient was measured at Mex=0.77 and Tu=16%. Relatively good agreement was found between the results of the two methods and the effect of recovery temperature and data reduction time was analyzed. Improvements were made to the experimental set up for the next comparison, a showerhead film cooled vane. This geometry was tested at BR=0, 2.0, Mex=0.76 and Tu=16%. The TFG and IR results did not compare well for heat transfer coefficient or film cooling effectiveness. The effects of measured and calculated recovery temperature were analyzed as well as the respective data reduction methods, though the analysis could not account for the effectiveness trend seen on the suction surface. Finally, a vane with showerhead and shaped film cooling holes were presented at BR=0, 1.7, 2.0, 2.8, Mex=0.85, and Tu=13% to assess a new film cooling geometry measured with the IR technique. Similarities on the suction surface trend between the different film cooled geometries tested with IR indicate a flaw in the experiment that will require further analysis, changes and testing to complete the comparison with TFG.