The Prediction of Burner Stability Limits

A flame extinction model is incorporated in a computational procedure containing the "k-epsilon-g" model of turbulence and applied to the prediction of burner stability features of some furnace trials performed at the international Flame Research Foundation. The fuels are low calorific value gases. As a prelude to the application, the lifting of and blow off of turbulent jet diffusion flames are examined as well as the stability behaviour of baffle stabilized premixed flames. The extinction model presumes that reaction will cease when the diffusional rate between the fine turbulence scales exceeds the reaction rate, both of which quantities are simply characterized. Its performance across the range of flows studied is remarkably good. Diffusion flame blow off is well represented by straightforward considerations of jet similarity and fuel stoichiometry.