旋转带肋直通道湍流流动TR-PIV实验

采用高频粒子图像测速系统(TR-PIV)测量了旋转带肋通道内的主流平均速度、雷诺切应力、再附点等参数,并研究其沿程变化规律,通道高宽比为1,肋的阻塞比为01,雷诺数为10 000,旋转数从0变化到052,实验结果表明:静止时流动呈对称分布,但旋转后产生的哥氏力会极大地影响通道内的湍流流动,随着转速的增加,主流速度型偏向后缘面,前缘面涡系结构不断增大,再附点不断后移,而后缘面正好相反,并且这种趋势会沿程发展;前缘面附近的雷诺切应力变得越来越弱,而后缘面则越来越强,沿程雷诺切应力极值基本不变,但下游区域有所扩大。 

Experiment of turbulent flow in rotating ribbed channel with TR-PIV

The mainstream averaged velocity, Reynolds stress and the reattachment point were measured in rotating ribbed channel with time-resolved particle image velocimetry(TR-PIV), and their change rule along the channel was studied. The aspect ratio of channel was 1, the blockage ratio of rib was 01, the Reynolds number was set to 10 000, and the rotation numbers ranged from 0 to 052. The experimental results showed that: the flow was symmetrical in static conditions, but Coriolis force generated by rotation would greatly affect the flow. With the increase of the rotating speed, the mainflow velocity pattern was inclined to the trailing side, the vortices structure on the leading side increased, and the attachment point moved backward, while the trailing side was just the opposite, and this trend would develop along the path; the Reynolds stress near the leading side became weaker, while the trailing side became stronger, and the extreme value of the Reynolds stress along the channel was basically the same, but the region would expand downstream.