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

This work is dedicated to the numerical modeling of hydrodynamics of an ann ular swirling decaying flow induced by means of a single tangential inlet i n laminar flow regime. Complete Navier-Stokes equations have been solved by a finite element method using the FIDAP package. We have shown that a corr ect numerical modeling is strongly linked to the mesh generation, the desig n of which is crucial. Indeed, the tangential inlet induces recirculating f lows, whose shapes and sizes are intimately depending on both the axial loc ation from the swirl generator and the azimuthal position with respect to t he tangential inlet axis. The swirl decay along the flow path has been char acterized using various profiles of both tangential and axial velocity comp onents, streamlines angles and local swirl intensity near both cylinders of the annulus. The mean swirl intensity in the whole annular gap thickness h as been found to decrease exponentially from the entrance section. (C) 1998 Elsevier Science S.A. All rights reserved.