Experimental Study on the Overall Cooling Effectiveness of Effusion-Cooling Ceramic Matrix Composite Platform

Ceramic matrix composite (CMC), with higher thermal limit and lower density relative to the superalloy, is regarded as the most important structural material for modern gas turbine engines. However, the anisotropic thermal conductivities caused by the weave patterns totally change the thermal conduction performance inside the solid domain. Therefore, the present study aims to use the infrared thermographic to measure the SiC/SiC composite platform with staggered effusion holes along with the superalloy platform. CMC platform is prepared by 2-D plain weave braid structure with chemical vapor infiltration (CVI) process. The temperature of mainstream is 900 K to match the real mainstream to coolant temperature ratio (T_g/T_c=1.5, 2.1). The experimental was conducted with seven mass flow ratios (MFR=1.5%–4.5%). The results indicate that the thermal conductivity along the thickness direction is of great importance for the CMC platform. The superalloy platform obtains higher level of overall cooling effectiveness than CMC at T_g/T_c=1.5. However, the CMC platform achieves greater overall cooling effectiveness relative to superalloy at T_g/T_c=2.1. In addition, CMC platform presents enhanced uniformity of overall cooling effectiveness due to the larger in-plane thermal conductivity.