Experiment of turbulent flow in rotating smooth channel using two-dimensional hotwire

The averaged velocities and Reynolds stresses were measured at different streamwise positions of a rotating smooth channel with two-dimensional hotwire. The results revealed that: the relatively high local rotation parameter expanded the influence region of rotation on the averaged velocity and induced the relaminarization of the turbulent flow near the leading side. The normalized averaged velocity profiles near the trailing side were strictly arranged in the rotation number order, and presented a logarithmic distribution in the log-law region. Meanwhile, all normalized Reynolds stress components were immune to rotation near the trailing side. Owing to the relaminarization, the normalized averaged velocity profiles near the leading side cannot maintain the logarithmic distribution in the log-law region, and all Reynolds stress components decayed with the growing rotation number and radius of the streamwise position. With the u-v quadrant analysis, the immediate reason of the relaminarization was attributed to the reduction of the generation of turbulent fluctuation.