Predictions of swirling flow in sudden-expansion dump combustor with flameholder side-inlet using two-step combustion model

The swirling flaw of sudden-expansion dump combustor with central V-gutter flameholder and six side-inlets is studied by employing the SIMPLE-C alogri thm and Jones-Launder k-epsilon two-equation turbulent model, Both combusti on models of one-step with infinite chemical reaction rate and two-step wit h finite chemical reaction rate of eddy-breakup (EBU) model are used to sol ve the present problem. The results agreed well with available prediction d ata in terms of axial-velocity and total pressure coefficient along combust or centerline. The flowfield structure of combustor considered is strongly affected by swirling, flameholder and side-inlet flow. For the fixed streng th of swirling, the length of central circulation zone is decreased when th e angle of V-gutter is increased. The outlet velocity of combustor in react ing flow is higher than that in cold flow because the released heat of comb ustion causes the decrease of density throughout the combustor flowfield. T he distribution of mass fraction of various species in reacting process dep ends on the mixing effect, chemical kinetic and the geometric configuration of combustor.