新型双壁结构涡轮叶片共轭传热研究

Multi-channel wall jet cooling structure is a novel internal cooling structure for gas turbine blades, which has advantages of less coolant consumption and low pressure loss. The simplified blade with wall jet cooling and GE-E3 blade are built, and their flow and heat transfer characteristics are studied comparatively by using the conjugate heat transfer method. The results show that the narrow space in the wall jet cooling channel suppresses the occurrence of crossflow, and cooling air forms streamwise vortices in the cooling channel; lots of coolant from air chamber at the leading edge flows through the cooling area on the suction side, and then is discharged from the trailing edge with low outlet pressure and large outflow area. The cooling air discharged from the film holes at the leading edge has lower flow rate and momentum, which contributes to better film coverage characteristics for cooling air on the outer surfaces of the blade; centrifugal force decreases the pressure at the root of the blade in the cooling chamber at the leading edge, which results in mainstream intrusion. Compared with the GE-E3 blade, the temperature and its gradient at the leading edge are lower for the blade with wall jet cooling, so multi-channel wall jet cooling has better cooling characteristics for the leading edge.