Influence of Axial Wall Slip on Swirl Velocity in a Laminar Microtube Flow

Abstract

The traditional method for improving the transport characteristics of flow inside microtube is attained by introducing swirling velocity at the entrance. Enhancing the fluid movement within such microtubes is crucial for applications demanding heat transfer or fluid mixing due to its laminar characteristics. In this present study, the laminar flow with swirl decay in a straight circular microtube is obtained analytically by considering axial wall slip. Rankine vortex in combination with axial slug velocity profile is considered for mathematical formulation. It is found that the analytical solution is a function of Reynolds number, transition radius, slip length, and the axial distance along the flow direction. In order to build swirl flow devices, present results provide the analytical formulae to evaluate the distribution of swirl velocity having axial wall slip. For flows when swirl and slip effects interact, a definite increase in average path travelled by the fluid is realised. We believe that the current work will be helpful in designing and improving the transport characteristics in circular microtubes.