As the core equipment of the power generation system, a gas turbine is an indispensable energy-converting device in the national industry. The flow inside a high-pressure turbine (HPT) is highly unsteady, which has a great influence on the aerothermal performance and structural strength. To better clarify the flow mechanism and guide the advanced design, the basic flow characteristics of transonic turbines are investigated in the paper by a modified scale-adaptive simulation (SAS) model based on the shear stress transport (SST) turbulence model. The numerical results reveal the formation and development of the secondary flow structures such as wake vortex, pressure wave, shock wave, and the interactions among them. The length and frequency characteristics of wake are in good agreement with the large eddy simulation (LES) and the experimental data. Based on the detailed flow information, the local loss analysis is performed using the entropy generation rate. In summary, the wake vortex-related flow is the main origin of unsteadiness and entropy loss in high-pressure turbine cascade.

中文翻译：

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跨音速涡轮尾流涡流相关流动机理的数值研究

燃气轮机作为发电系统的核心设备，是国民工业中必不可少的能量转换装置。高压涡轮（HPT）内部的流动非常不稳定，这对空气热性能和结构强度有很大影响。为了更好地阐明流动机理并指导先进的设计，本文通过基于剪应力传输（SST）湍流模型的改进比例自适应模拟（SAS）模型研究了跨音速涡轮机的基本流动特性。数值结果揭示了次级流动结构的形成和发展，如尾涡，压力波，冲击波以及它们之间的相互作用。尾流的长度和频率特性与大涡模拟（LES）和实验数据非常吻合。基于详细的流量信息，使用熵产生率执行局部损失分析。总之，与尾涡相关的流动是高压涡轮叶栅中不稳定和熵损失的主要根源。