On the self-constraint mechanism of the cross-stream secondary flow in a streamwise-rotating channel

The mechanism underlying the magnitude-reverse phenomenon of the mean spanwise velocity with respect to an increasing rotation number in a streamwise-rotating channel flow is investigated through a budget balance analysis of Reynolds shear stress u2 ' u3 '. It is found that u2 ' u3 ' imposes a negative feedback to itself through the production term, which prevents its magnitude from increasing monotonically with an increasing rotation number. This behavior of u2 ' u3 ' further leads to the magnitude reverse in the spanwise wall shear stress and mean spanwise velocity in the near-wall region.