Effects of mid-passage gap on endwall purge flow film cooling

Numerical Simulations were performed to study the effects of mid-passage gap on endwall purge flow film cooling. Film cooling performance from upstream slot purge flow with and without mid-passage gap was examined in detail. The effects of mass flow ratio and jet angle of purge flow from the mid-passage gap were studied. Results show that the mid-passage gap could restrict the spreading of the upstream purge flow over the endwall surfaces. The mid-passage gap significantly affected cooling coverage near the suction side and the downstream region of the endwall passage. In addition, the purge flow from the mid-passage gap could reduce the purge flow cooling performance on the endwall when the mid-passage purge flow was improperly applied. The effects of the jet angle of the mid-passage gap on endwall purge flow cooling were limited, which could only alter the film cooling distributions slightly in some local areas on the endwall.