Compressible Direct Numerical Simulation of Low-Pressure Turbines: Part II — Effect of Inflow Disturbances
Compressible Direct Numerical Simulation of Low-Pressure Turbines: Part II — Effect of Inflow Disturbances
复制标题
低压涡轮机的可压缩直接数值模拟：第二部分 - 流入扰动的影响
DOI：
10.1115/gt2014-25689
复制
发表时间：
2014
影响因子：
2.8
通讯作者：
R. Sandberg
中科院分区：
文献类型：
--
作者：
V. Michelassi;Liwei Chen;R. Pichler;R. Sandberg
本文对T106叶栅内的可压缩流动进行了直接数值模拟。各种环境变量，即背景湍流水平、进入尾流的频率和雷诺数，以及这些变量的组合被考虑用于总共12个完全解析的模拟。本文系统地研究了所观察到的流动现象的机理，包括来流的混合和畸变、尾流/边界层相互作用以及边界层演化对叶型损失产生的影响。详细的损失生成分析允许识别边界层和流动核心中的每个损失源。特别注意的是专门用于协调一致的影响唤醒畸变力学和间歇性的非定常边界层。此外，本研究探讨了Boussinesq涡动粘度假设的有效性，它调用了常用的RANS模型中的线性应力-应变关系。使用时间和相位锁定平均流场来仔细检查源自该假设的误差，以可能识别传统RANS模型的缺点。版权所有© 2014 by ASME
In the present paper, direct numerical simulation (DNS) studies of the compressible flow in the T106 linear cascade have been carried out. Various environmental variables, i.e. background turbulence level, frequency of incoming wakes and Reynolds number, and a combination of these were considered for a total of 12 fully resolved simulations. The mechanisms dictating the observed flow phenomena, including the mixing and distortion of the incoming wakes, wake/boundary layer interaction, and boundary layer evolution impact on profile loss generation are studied systematically. A detailed loss generation analysis allows the identification of each source of loss in boundary layers and flow core. Particular attention is devoted to the concerted impact of wakes distortion mechanics and the intermittent nature of the unsteady boundary layer. Further, the present study examines the validity of the Boussinesq eddy viscosity assumption, which invokes a linear stress-strain relationship in commonly used RANS models. The errors originating from this assumption are scrutinized with both time and phase-locked averaged flow fields to possibly identify shortcomings of traditional RANS models.Copyright © 2014 by ASME