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Abstract With the rapid development of modern gas turbines and aeronautical engines, temperature at the combustor outlet is consistently increasing, leading to an intensified interaction between combustor and turbine. Meanwhile, the turbulence, residual swirl, and presence of hot streak at the combustor outlet exert a considerable influence on the downstream turbine, notably affecting blade aerodynamics and heat transfer dynamics. Nowadays, significant research efforts have been focused on the coupled system of combustor and turbine, aiming to elucidate the flow dynamics and migration patterns of hot streak under complex interactions. This study presents a setup comprising a three-sector combustor and six turbine guide vanes (TGVs) equipped with advanced lean-burn dual-stage swirlers. Temperature distribution at the combustor outlet in the coupled system is measured through a high-temperature dual-axis displacement system. Numerical simulations are conducted to reveal the initiation and progression of hot streak within the combustor, operating within the coupled system. Moreover, the study investigates the impact of various contraction ratios on the mixing characteristics of gas and coolant within the combustor, as well as the migration process of hot streak in turbine guide vanes in the coupled system. Overall, numerical results indicate that the influence zone of the TGVs on the pressure within the combustor can reach the position of the dilution holes, significantly affecting both the depth and mixing characteristics of the jet from the dilution holes. As the contraction ratio increases, there is an observed increase in the outlet temperature distribution factor (OTDF) within the combustor, which is attributed to reduced mixing effects. Conversely, at the TGVs’ outlet, an increased flow velocity and improved mixing effects in the TGVs’ flow channel contribute to a more uniform temperature field. Furthermore, the clocking position of TGVs in this study is found to impede the mixing of coolant in various flow channels. This highlights the significance of establishing a correlation between TGVs’ clocking position and the inlet hot streak.
Lyu et al. (Mon,) studied this question.