Experimental and computational investigation of turbine cooling designs incorporating a thermal barrier coating

Few studies in the open literature have investigated the effect of thermal barrier coatings (TBC) on gas turbine component thermal protection designs. The current study evaluated shaped hole film cooling and internal cooling enhanced with rib turbulators separately as well as part of an integrated design incorporating a TBC. The design and construction of a matched-Biot number test section is discussed along with an evaluation of uncertainty. Enhanced internal cooling was found to provide a 44% increase in overall effectiveness without a TBC. The TBC provided a 47% increase in spatially-averaged effectiveness on the metal-TBC interface. The optimum velocity ratio with a TBC was shown to be lower than that without a TBC as the internal cooling effects were reduced with the extraction of coolant. A RANS conjugate heat transfer study closely predicted the performance of the configurations tested without a TBC, but over-predicted the effectiveness of designs incorporating a TBC.