Investigation of a nozzle guide vane cooling characteristic under one engine inoperative conditions

The film cooling characteristics of turboshaft engine vanes were studied under one engine inoperative (OEI) conditions. Variations in the operating conditions caused tremendous changes in Reynolds number (Reg), turbulence intensity (Tu) and swirling inflow of the mainstream. Therefore, pressure-sensitive paint (PSP), as a promising measuring technique, was adopted for analyzing the impacts of Reg and Tu on the vane film cooling effectiveness. Furthermore, numerical methods were utilized to explore the film cooling effectiveness of vanes with two different hole shapes under various swirling inflow conditions. The results indicated that enhancement in either Tu or the swirling inflow decreased the film cooling effectiveness. However, Reg had little effect on the film cooling performance within the studied range. The area-averaged film cooling effectiveness decreased by 5.6% when Tu increased from 15% to 30%. In addition, the vane film cooling performance was greatly impacted by swirling inflow. The film cooling effectiveness exhibited continuous decreases as the swirling angle (SA) increased, especially for the vane with shaped holes; its maximum area-averaged film cooling effectiveness reduction was 28.9%. Overall, OEI conditions mainly altered the Tu and swirling inflow, thus changing the aerothermal performance, while Reg remained relatively unchanged in this research. The present research aimed to contribute to designing the turbine cooling under OEI conditions.