Paper Title
Three Dimensional CFD Modeling of Turbulent Flow Through Circular Tube Using Swirl Generator Vanes at Different Positions

Abstract
This paper presents a numerical three dimensional CFD modeling of the air swirl flow characteristics generated in a circular tube using swirler vane blades. The purpose is to achieve a numerical solution that can offer a powerful insight into the performance characteristics of the swirl flow generator on a scale and level of details not always possible with conventional experimental methods. The modeling was extended to study the key design parameters of swirler angular velocity, relative position of swirler vanes inside the tube, and air flow velocity on the thermo-fluid characteristics with the particular reference to traditional plain tube. Finite volume discretization method using body-fitted coordinates and a SIMPLEC-based solution algorithm were applied with a segregated solver. The momentum and energy equations were solved by the second order upwind scheme. The fluid flow and heat transfer through the tube was treated using k-􀀀 Realizable turbulence model with enhanced wall treatment. The local distributions of the flow velocity and pathline of the swirl vanes were presented. The performance criteria of heat transfer per unit pumping power and enhancement efficiency index were discussed. Better values of enhancement efficiency index were obtained at lower values of both Reynolds number and angular velocity.