Numerical solution of nonpremixed reactive flows in a swirl combustor model
Abstract
A mathematical model has been developed to study turbulent, confined, swirling flows under reacting nonpremixed conditions. The model solves the conservation equations of mass, momentum, energy, species, and two additional equations for the turbulent kinetic energy and the turbulent length scale. Combustion has been modelled by means of a onestep overall chemical reaction. The numerical predictions based on the eddybreakup model of turbulent combustion show a recirculation zone in the form of a onecelled toroidal vortex at the combustor centerline. High levels of turbulence characterize the recirculation zone, whose diameter and velocity first decrease and then increase as the magnitude of the outer swirl number is first decreased from counterswirl to zero and then increased to coswirl flow conditions. Counterswirl produces steeper velocity gradients at the interjet shear layer, promotes faster mixing and yields better combustion efficiency than coswirl. The numerical results are compared with those obtained under nonreacting conditions in order to assess the influence of the heat release on the size of the recirculation zone.
 Publication:

Engineering Computations
 Pub Date:
 June 1984
 Bibcode:
 1984EngCo...1..173R
 Keywords:

 Combustion Chambers;
 Computational Fluid Dynamics;
 Mathematical Models;
 Swirling;
 Turbulent Flow;
 Boundary Value Problems;
 Chemical Reactions;
 Combustible Flow;
 Combustion Efficiency;
 Conservation Equations;
 Counterflow;
 Flame Stability;
 Hydrodynamic Equations;
 Fluid Mechanics and Heat Transfer