Influence of flow swirl on the velocity and temperature distribution in a tube of circular cross section

The Navier-Stokes equations for steady laminar incompressible fluid flow, made to swirl at the tube inlet, is solved by a numerical method, and the velocity profiles at various cross-sections along the tube length are computed. It is shown that swirling changes the axial velocity profile by shifting the maximum from the axis toward the walls, and that at critical values of the swirl, reverse flows form along the axis.