旋转方截面U型通道分离流二阶相关分量测量

为了深入了解旋转涡轮叶片内冷通道中的紊流特性，并为CFD研究提供实验数据，用激光多普勒测速仪（LDA）测量了旋转U型通道中分离流的雷诺应力分量。通道的转轴与弯道的曲率轴平行，测量是在与转轴垂直的对称平面中进行的，流动状态为Re=100,000,Ro=0,0.2和－0．2。直接测量的分量为ux^2^-,Ux^2^-和uxux^-，结果表明旋转对紊流分布的形式有很强的影响。在测量的三种旋转状态中Ro=0.2的正转和Ro=0.2的负转分别具有最低和最高的紊流强度。根据测量到的信息估算了雷诺应力uiuj^-的产生率，结果显示负转的产生率比正转时高。

Double correlations measurement of turbulent separated flow through rotating square U bend duct

The LDA measurement results of double correlation of the separated flow in a U bend duct rotating around a axis parallel with the bend axis is discussed.The measurement is made in the symmetry plane perpendicular to the rotating axis with Re =100,000,and Ro =0,0.2,or 0.2 respectively.The components of double correlation directly measured are u 2 x , u 2 z and u xu z ,The results show that rotation has strong influence on turbulence distrbution pattern.Among the three rotating cases.positive rotation with Ro =0.2 has lowest and negative rotation has strongest turbulence intensity.Based on the measured information the generation rate of Reynolds stress u iu j is estimated,the results show that negative rotation has higher generation rate than positive rotation.