Overall Cooling Effectiveness of Effusion Cooled and Thermal Barrier Coated Swirl Stabilized Liquid Fueled Combustor Liner in Reacting Flow Conditions

The combination of effusion cooling and thermal barrier coating has enabled to reach higher combustor temperatures, hence more efficient and powerful gas turbine engines over the last two decades. Effusion cooling and thermal barrier coating are favored for their low amount of coolant demand, high effectiveness and uniform structure. Moreover, it is also utilized in afterburner systems to pursue desired thrust for sufficient time. The main purpose of the present research is to provide overall cooling effectiveness and heat transfer calculation method for state-of-art effusion cooled and thermal barrier coated (TBC) gas turbine combustion chambers. The rig has been designed to run in a reacting flow and to provide realistic conditions of a swirl stabilized, liquid fueled can type combustor with TBC and effusion cooling. The test campaign covered equivalence ratio from 0.35 to 0.6 and with a static pressure drop of 1%. The liner is laser drilled to obtain shallow holes with an angle of 25 degrees to form the effusion cooling scheme. The hole density is set to have staggered arrays with s/d = 9, which is considered to be a high hole density for TBC coated liners. Metal temperature measurements are taken with thermocouples from five equidistant axial locations. To develop simple 1D heat transfer method, while Net Heat Flux Reduction coefficient is generated from test data, effective flow area of flame side is calculated from CFD analysis. 1D thermal solver and coefficients are validated by means of different equivalence ratio and adiabatic flame temperatures.