Turbine vane film coolants migration influenced by combustor swirl

This paper investigates vane film coolants migration situations and aerodynamic characteristics of the aeroengine high pressure turbine first stage cascades with the influence of combustor residual swirl. The aggresive outflow conditions of advanced lean-burn premixing combustor dramatically impact the working performance of downstream turbine components. The migration of vane film coolants is also remarkably influenced thus having effect on the cooling performance on both stator vane and downstream blade surface. Cases with different swirl directions, strengths and clock-wise positions are numerically simulated and analyzed. The results show that cases with strong swirl have 13-19% larger vane cascade total pressure loss and 5-8.5% larger blade total pressure loss, compared to their corresponding cases with weak swirling flow. The coolants mass flow distribution patterns in the film hole row are mainly determined by the swirl direction. The discrepancies in film hole coolants mass flow at different span-wise positions are larger with stronger residual swirl. The vane film coolants from different origins hardly interacts with each other on the vane surface. The cooling performance at vane corner zones is impacted by the swirling flow. With weaker swirling flow, more vane film coolants can cover on blade surface and have higher cooling effectiveness. However, the averaged vane film cooling effectiveness on blade surface is only about 0.085. While combined with combustor liner coolants, considerably phantom cooling performance exists at blade suction surface near tip and hub endwall. The conclusions indicate that stronger swirling flow leads to poorer aerodynamic and cooling performance. Influences of upstream flow structures should be considered when designing the cooling configurations of rotor blade. Investigations of this article give better understanding on the influence mechanisms of combustor residual swirl on the vane film coolants migration and provide reference for turbine cascade optimization and robust cooling structure design.