Finite-element simulation of laminar swirling decaying flow induced by means of a tangential inlet in an annulus Original Research Article

This work is dedicated to the numerical modeling of hydrodynamics of an annular swirling decaying flow induced by means of a single tangential inlet in laminar flow regime. Complete Navier-Stokes equations have been solved by a finite element method using the FIDAP package. We have shown that a correct numerical modeling is strongly linked to the mesh generation, the design of which is crucial. Indeed, the tangential inlet induces recirculating flows, whose shapes and sizes are intimately depending on both the axial location from the swirl generator and the azimuthal position with respect to the tangential inlet axis. The swirl decay along the flow path has been characterized using various profiles of both tangential and axial velocity components, streamlines angles and local swirl intensity near both cylinders of the annulus. The mean swirl intensity in the whole annular gap thickness has been found to decrease exponentially from the entrance section.