Potential flow in helical pipes (Q1090540)

We have studied the potential flow in a helical pipe using an orthogonal system of coordinates fixed to the helical axis. The analysis was conducted both analytically by applying perturbative methods and numerically. The results show that the torsion of the helical axis has little effect on axial velocity in a torus provided with the same curvature of the helix. At the same time it induces a large secondary flow that is expected to have a relevant effect on the boundary layer on the walls of the helical pipe.