Flow through a helically coiled annulus

Abstract

In this paper the flow is studied of an incompressible viscous fluid through a helically coiled annulus, the torsion of its centre line taken into account. It has been shown that the torsion affects the secondary flow and contributes to the azimuthal component of velocity around the centre line. The symmetry of the secondary flow streamlines in the absence of torsion, is destroyed in its presence. Some stream lines penetrate from the upper half to the lower half, and if λ is further increased, a complete circulation around the centre line is obtained at low values of λ for all Reynolds numbers for which the analysis of this paper is valid, λ being the ratio of the torsion of the centre line to its curvature.