Flow through a rotating helical pipe with circular cross-section

The incompressible viscous steady flow through a helical pipe of circular cross-section rotating at a constant angular velocity about the centre of curvature is investigated numerically to examine the combined effects of rotation (Coriolis force), torsion and curvature (centrifugal force) on the flow. It is found that the variation of the total flux with rotation shows a sharp peak when the direction of rotation is negative, that is, in the opposite direction to the pressure-driven flow. The total flux decreases at large rotation. As the torsion increases, the flux first decreases from that of the toroidally curved pipe, reaches a minimum and then increases when the rotation is positive or negative large value. The secondary flow structure in the cross-section of the helical pipe is one cell type when the flux is close to the maximum. There is no bifurcation of the flow. (C) 2000 Elsevier Science Inc. All rights reserved.