Swirl effects on confined flows in axisymmetric geometries

In this paper the results of an experimental investigation of turbulent swirling flows in a model of a coaxial dump combustor are presented. The objectives of this study are twofold: first, to investigate, understand, and document the effects of inlet swirl on the characteristics of a dump combustor flowfield; second, to provide benchmark experimental data to aid the development of advanced design codes. Two sets of experiments were carried out. The first set examined the effect of swirl number on the flowfield characteristics. The second set studied the effect of inlet swirl profile and its evolution throughout the combustor. The results indicated that swirling motion altered the flowfield and significantly reduced the length of the corner recirculation region. Furthermore, specification of swirl strength is not an all inclusive parameter for swirl performance classification and characterization.