Effects of Combustor Residual Swirl and Hot Spot on Aerothermal Characteristics and Cooling Performance of Gas Turbine Blade

Abstract The swirling flow and the hot spot generated in the aero-engine combustor have significant impacts on the downstream turbine components. This article numerically investigates the influence of the residual swirl clocking position, direction, and the hot spot on the aero-thermal characteristics of the turbine stage cascades and the cooling performance of the rotor blades. Computational results show that the negative residual swirl increases the turbine stage total pressure loss by about 3–5% while the hot spot leads to 1.5–2.5% total pressure loss reduction. The aero-thermal characteristics and the cooling performance of the rotor blade are scarcely influenced by the residual swirl clocking positions. The hot spot decreases the mass flow of the blade tip holes by 2%, compared to the cases with a uniform temperature inlet. The negative residual swirl makes the coolants at the pressure surface develop further downstream, reduces the differences in the leading edge holes mass flow at different spanwise positions, and brings more intense heat transfer at the tip and better cooling performance at the blade surface. The flow capacity and the working performance of the turbine stage are also almost unaffected by the residual swirl and hot spot. This article presents a numerical method for turbine stage cascades with the residual swirl and the hot spot, analyzes the impact of combustor outflow conditions on turbine stage performance, and provides a reference for computational fluid dynamics-aided design of turbine aerodynamic and cooling configurations.