Effect of multi-cavity on the aerothermal performance robustness of the squealer tip under geometric and operational uncertainties

Abstract

A multitude of uncertainties intertwined within the manufacturing and functioning of gas turbines has often been overlooked in numerous prior investigations regarding the aerothermal performance of blade tips. Consequently, the actual lifespan of the blades falls considerably short of the initially anticipated duration. This study proposes an efficient parallel turbo robustness analysis framework and aims to delve into the uncertain characteristics exhibited by various multi-cavity squealer tips during real-world gas turbine operations. The findings of this research reveal that the inclusion of ribs has an adverse impact on the flow field, leading to heightened chaotic tendencies and a considerable reduction in the expected aerodynamic efficiency of the multi-cavity squealer tip. The leakage flow experiences a notable increase, reaching values of 22.30%, 17.88%, and 24.51% for the three distinct multi-cavity configurations, surpassing the corresponding value of 13.63% observed for the conventional squealer tip. However, integrating the flow field uncertainty into the thermal field uncertainty proves challenging due to the disruption of the cavity vortex system caused by the pressure side ribs. Thus, the heat transfer performance of the multi-cavity squealer tip exhibits superior robustness compared to that of the conventional squealer tip. Furthermore, this paper introduces a novel evaluation index, based on comprehensive uncertainty flow and thermal analyses, to assess the robustness of the aerothermal performance. The present work makes a valuable contribution to the development of digital twins for turbomachinery systems.