Conjugated investigation on the effect of rotation on the leading-edge impingement structures with and without film-cooling holes

Abstract

A thermal-fluid-structure conjugate analysis is carried out to analyze the temperature and Von Mises stress distribution of impingement structures with and without film-cooling holes. The flow structures under stationary and rotating conditions are compared and the effect of the introduced Coriolis force in rotating channels is analyzed in detail. Turbulence model verification is accomplished by comparing the critical parameters from the experiments that involve mainstream flow and impingement cooling. Several cases of different Reynolds numbers were stimulated and the results indicate that the impingement cooling performance under rotating conditions is worse than that under stationary conditions, due to the centrifugal force enhancing the cross-flow effect in the impingement chamber. The film-cooling hole arrangement can reduce the temperature and achieve a more uniform temperature distribution at the leading edge of the blade. Compared to rotating cases, the stationary cases produce higher stress for all Reynolds numbers. For the pure impingement structure, the maximum stress region appears at the root of the blade while the maximum stress of the impingement structure with film-cooling holes locates at the exit of the film-cooling hole. Though the impingement structure with film-cooling holes achieves lower average stress of the leading edge, the maximum value of the stress is higher than the pure impingement structure.