Abstract
Turbulent nonpremixed swirl-stabilized flames are common in practical combustors and form the next level of complexity after piloted and bluff-body stabilized flames. Modeling swirling flows remains a challenge especially when the swirl level is high enough to induce vortex breakdown and recirculation. This paper presents experimental results on the velocity field and the stability characteristics of a new swirl burner which has well-defined boundary conditions. This burner is capable of stabilizing turbulent nonpremixed flames which have high swirl numbers and which may have a significant degree of turbulence-chemistry interactions. A Monte Carlo-based probability density function (PDF) method is also used to compute the same turbulent, highly swirling flame using the simplest models for velocity (SLM), turbulent frequency (JPM), and molecular mixing (IEM). A single flamelet library is used here to represent chemistry. These simple computations reproduce the correct flow structure and compare well with the measured velocity field. Refinements to the computations and more extensive measurements in such flows are forthcoming.