Effects of cooling supply strategy and endwall misalignment on aerothermal performance of turbine vane with connected slot–slashface layout

The first-stage turbine vane endwall is subjected to extremely high thermal loads and operates within a complex flow environment. To mitigate the endwall thermal load, the unavoidable gaps such as the slot and slashface, together with arranged film-cooling holes, are employed as coolant passages. However, the configuration of multi-source coolant and the endwall misalignment caused by thermal expansion or assembly can significantly influence the vane aerodynamic and endwall thermal performance. Understanding these interactions is crucial for improving turbine cooling efficiency and ensuring reliable engine operation. In the current work, the numerical method is employed to investigate the effects of coolant supply strategies and endwall misalignment modes on the vane endwall aerothermal performance with the upstream film holes and the realistic connected slot–slashface cooling structure. The results demonstrate the necessity of considering the actual connected slot–slashface structure, since interactions occur between the coolant supplied from these two features. Increasing the coolant supply to the slashface not only enhances the film-cooling effectiveness on the suction-side endwall and prevents the mainstream ingestion, but also compensates for the slot coverage on the pressure-side endwall, thereby increasing the overall endwall film coverage to 49.8%. Moreover, the endwall misalignment can increase the flow rate of mainstream ingestion and potentially decrease the endwall overall film-cooling performance. The endwall aerothermal performance is particularly sensitive to the movement of the suction-side endwall. When the suction-side endwall moves downward, the coolant accumulates toward the suction-side endwall and enhances the local cooling effectiveness. However, the mainstream ingestion through the slashface increases by 18.3% at the same time compared with that of align endwall mode. These findings highlight the importance of considering the integrated slot–slashface gap configuration. The coolant supply strategies and endwall misalignment should be investigated based on this connected gap to more realistically assess endwall aerothermal performance and guide turbine cooling design. • Connected slot–slashface gap is established to model realistic endwall configuration. • Coolant supply strategies and endwall misalignment are numerically studied. • Increased slashface flow improves coverage and compensates for slot cooling. • Endwall misalignment increases ingestion and may degrade cooling performance. • SS-endwall misalignment causes the most pronounced changes in aerothermal performance.