Numerical Investigation of the Effects of Rising Angle on Intermediate Turbine Duct and Nearby Turbines

作     者：LIU Hongrui JI Lucheng LIU Jun DU Qiang LIU Guang WANG Pei DU Meimei 

作者机构：School of Aerospace Engineering Beijing Institute of Technology Laboratory of Light-duty Gas-turbine Institute of Engineering Thermophysics Chinese Academy of Sciences Petroleum Production Engineering Research Institute of Huabei Oilfield Company 

出 版 物：《Journal of Thermal Science》 (热科学学报(英文版))

年 卷 期：2017年第26卷第5期

页      面：421-430页

核心收录：

学科分类：08[工学] 082502[工学-航空宇航推进理论与工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0825[工学-航空宇航科学与技术] 0702[理学-物理学] 

基　　金：supported from the National Natural Science Foundation of China(No.51406204) 

主　　题：Intermediate Turbine Duct Rising Angle Flow Field Analysis 

摘      要：In order to improve the efficiency, ultra-high bypass ratio engine attracts more and more attention because of its huge advantage, which has larger diameter low pressure turbine(LPT). This trend will lead to aggressive(high diffusion) intermediate turbine duct(ITD) design. It is necessary to guide the flow leaving high pressure turbine(HPT) to LPT at a larger diameter without any severe loss generating separation or flow disturbances. In this paper, eight ITDs with upstream swirl vanes and downstream LPT nozzle are investigated with the aid of numerical method. These models are modified from a unique ITD prototype, which comes from a real engine. Key parameters like area ratio, inlet height, and non-dimensional length of the ITDs are kept unchanged, while the rising angle(radial offset) is the only changed parameter which ranges from 8 degrees to 45 degrees. In this paper, the effects of rising angle(RA) on ITD, as well as nearby turbines, will be analyzed in detail. According to the investigation results, RA could be as large as 40 degrees in such model of this paper to escape separation; When RA increases, local inlet flow field of LPT nozzle appears to be with apparent variation; while a positive result is that outlet flow field could be kept almost unchanged through modifying blade profile. On the other hand, it seems optimistic that the overall total pressure loss could be kept nearly equivalent among different RA cases. And a valuable conclusion is that outer wall curvature is more important for pressure loss, which advises a clear direction for optimizing ITD.