Large-Eddy Simulation of Flame Dynamics During the Ignition of a Swirling Injector Unit and Comparison With Experiments

Abstract During the ignition of a swirled single-injector combustor, two phases have been identified experimentally. In first, flame penetrates injection unit, while in second, lifts off after substantial delay before stabilizing at distance from injector. This transient phenomenon is investigated using Large Eddy Simulations based on an Euler–Lagrange description liquid spray, energy deposition model to mimic ignition, and thickened combustion model. It shown that initial penetration injector unit linked with positive pressure excursion induced by rapid volumetric expansion burnt gases. sudden itself due fast increase heat release rate occurs during initiation process. The corresponding negative disturbances induce reduction mass flow through injector, followed acceleration return nominal value. also root disappears another delay, which results edge lifting stabilization exhaust steady operation device. relatively long time this liftoff takes place found correspond residence cooled gases vicinity chamber walls, are ultimately entrained internal recirculation zone quench lower foot.