Conjugate heat transfer simulation the impact of CMAS non-uniform deposition on the cooling effectiveness of a coated C3X vane

Abstract

This study developed a coupled heat transfer and deposit layer dynamic growth model to evaluate the nonuniform deposition behavior of CMAS particles and its impact on the cooling effectiveness of coated C3X high-pressure turbine vanes. Results show that particle accumulation creates protruding deposits at the leading edge and ridge-like deposits at the trailing edge. The low thermal conductivity of TBCs causes the coated vane’s surface temperature and deposit mass to rise significantly, approximately 27.0 K and 47 %, after 9000 h compared to the uncoated vane. Higher deposit surface temperatures increase pressure side temperatures, reducing heat transfer to the vane and lowering internal temperatures. In the absence of deposition, suction side temperatures decrease for both coated and uncoated vanes. Particle impacts increase linearly over time, influenced by diameter, with less effect for particles larger than 11 μm. The coated vane’s higher surface temperature results in a significantly higher particle deposition rate. After 9000 h, deposition efficiency for the coated vane rises from 2.96 % to 4.36 %. As deposition efficiency improves, overall cooling effectiveness increases over time, particularly at the leading and trailing edges, with the average increment rising from 9.4 % to 13 %.