Modeling of turbulent, swirling flow confined coaxial jet configuration

Abstract

A finite volume code that uses the STh-fPLEC algorithm to solve pressure-velocitycoupling has been developed for cylindrical combustor geometries as an aid to reducedpollutant emission design and operation of combustion systems. The method involves astaggered grid system for axial and radial velocities, a line relaxation technique for efficientsolution of the equations, and standard k-£ turbulence model.The code is used to predict turbulent swirling gas velocity field in confined coaxial jetconfiguration and the gas flow within the combustor is assumed to be steady-state,axisymmetric, non-reacting, isothermal and incompressible.The predictions are compared with an experimental and a previous numerical study.The mean velocity profile predictions of the present study are in good agreement with theexperimental results, and are better than the numerical study which uses the same turbulencemodeL The turbulent kinetic energy of the gas, however, is underpredicted by this turbulencemodel, especially in the inner mixing region of the two jets. The reasons for the discrepanciesand the consequential value of the calculation method are discussed.