Hot wire test on the flow fields in a rotating square channel

To apply the hot wire technique in rotation condition and accurately measure the flow fields in a rotating square channel, a rotating test rig was built.Two connection modes were applied in the hot wire calibration tests, and the relative error in measuring the averaged velocity was estimated to be ±6%. The measurements were conducted in a rotating channel with the Reynolds number and rotation number varying in the range of 5 000-10 000, and 0-0.222, respectively. The results show that there is a shift of the velocity profile to the trailing side(Y/D=-0.5), the drift of velocity profile increases with the bigger X/D and rotation number. When the rotation number is 0.222, there is a velocity profile inflection point near the trailing side that likely is related to the secondary flow induced by Coriolis force instability.