Phase-Locked Investigation of Secondary Flows Perturbed by Passing Wakes in a High-Lift LPT Turbine Cascade
Phase-Locked Investigation of Secondary Flows Perturbed by Passing Wakes in a High-Lift LPT Turbine Cascade
复制标题
高扬程 LPT 涡轮叶栅中通过尾流扰动的二次流的锁相研究
DOI：
10.1115/gt2015-42480
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
F. Bertini
中科院分区：
文献类型：
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作者：
Daniele Infantino;F. Satta;D. Simoni;M. Ubaldi;P. Zunino;F. Bertini
本文介绍了在热那亚大学空气动力学和涡轮机械实验室进行的实验研究，目的是表征受来流扰动的高升程低压涡轮机叶栅中二次流的非定常特性。在名义出口雷诺数为300000的5叶大型线性叶栅中进行了研究。应用热线锁相系综平均技术，对尾流期下游切向平面内的速度和湍流强度随时间的分布进行了深入分析。一个多旋转技术已被用来测量的三个速度分量以及雷诺应力张量项。所获得的数据中的相位相关的平均速度，湍流和涡度的地图，以区分由于传入的尾流速度缺陷和那些由于相依赖的二次流结构上的尾流所携带的湍流的贡献。结果清楚地表明，当上游尾流通过测量区域时，通道涡发生了显著的扭曲和减弱。在尾流阶段，通道涡位置也发生了明显的位移。该分析有助于了解稳态和非稳态运行时出口流场的三维时间平均结构的差异。Copyright © 2015 by ASME
The present work describes the experimental investigations carried out at the Aerodynamics and Turbomachinery Laboratory of Genoa University aimed at characterizing the unsteady features of the secondary flows in a High-Lift Low Pressure Turbine cascade perturbed by incoming wakes. The investigations have been carried out at the nominal exit flow Reynolds number of 300000 in a 5-blade large-scale linear cascade. Hot-wire phase-locked ensemble-averaging technique has been applied to analyze in depth the time-dependent velocity and turbulence intensity distributions in a downstream tangential plane during a wake period. A multiple rotation technique has been used in order to measure the three velocity components as well as the Reynolds stress tensor terms. Acquired data are presented in terms of the phase-dependent mean velocity, turbulence and vorticity maps in order to distinguish between the contributions due to incoming wake velocity defect and those due to the turbulence carried by wakes on the phase-dependent secondary flow structures. Results clearly highlight a significant distortion and weakening of the passage vortex when the upstream wake passes through the measuring domain. Also an evident displacement of the passage vortex position has been observed in the wake period. This analysis allows understanding the difference in the three dimensional time mean structures of the exit flow field between the steady and unsteady operations.Copyright © 2015 by ASME