UNSTEADY INTERMITTENT FLOW IN A ROTATING CURVED PIPE

The effects of rotation and intermittent frequency on the flow transition of secondary flow and, main flow were examined in detail. Certain hitherto unknown flow patterns were found. A numerical study was performed to study the characteristics of unsteady intermittent flow in a rotating curved pipe. Due to the rotation, both the Coriolis force and the centrifugal force could contribute to the unsteady intermittent flow and some complicated phenomena can be found. The results indicate that the unsteady intermittent flow are mainly characterized by five parameters: the Dean number Dn, the curvature κ, the maximal force ratio F (of the Coriolis force to the centrifugal force in a cycle), the intermittent frequency parameter η (the ratio of a pulslating time to the cycle period), and the Womersley number α. Present works shows the natures of the unsteady intermittent flow in a rotating curved pipe.