Preliminary investigation of a swirl stabilized premixed combustor

Experiments were conducted in a swirl stabilized premixed combustor at atmospheric pressure in order to study the stability and structure of lean premixed methane air flames. Swirl number of the combustor was 0.74. The lab scale combustor was operated up to 30 kW of thermal power during measurements. Experiments focused on two main aspects of the combustion system. First the relation between the cold flowfield and the flame stabilization is examined. It is observed that, the structure of the flame near the dump plane corresponds closely to the features of the non-reacting air flowfield. The flame is seen to be stabilized on the boundary of the recirculation region. Lean blowout limits of the combustor that operates within the flamelet regime were also recovered. A correlation linking the blowout equivalence ratio to laminar flame speed is presented.