This paper is concerned with computations of a swirl-stabilized model tubo-annular combustor under isothermal conditions. The flow comprised a swirl-driven recirculation, two rows of radially injected jets, and an exit nozzle. The computations were based upon numerical solution of time-averaged transport equations for mass, momentum, turbulence energy, and dissipation using a finite-volume formulation. The combustor geometry was split into two zones, and the flow in the exit nozzle was computed using a general method for complex geometries. Laser-Doppler anemometry measurements of the velocity and turbulence fields were used to assess the performance of the numerical model. Predicted velocity distributions showed favorable agreement with measurements in the primary and intermediate zones although discrepancies increased in the dilution region. Predicted levels of turbulence energy were too low in regions of high anisotropy. A parametric study over the measured range of flow patterns indicated that local velocities were subject to errors of 30% in some small regions of the flow, but the mathematical model did simulate all observed trends. Further, it was demonstrated that, for isothermal flow, important global aspects of the flow (e.g., primary zone recirculation ratio) could be represented with acceptable accuracy for preliminary design purposes.
