Influence of the lug turbulator on flame dynamic characteristics

The strut flameholder is a key component of the multi-mode ram combustor. The stabilization zone has the characteristics of refluxes coupling and shear layers dispersion, the flame stability is difficult and the flame structure presents complex dynamic characteristics. A strut flameholder with/without lug turbulator was taken as the research model, a high-frequency ICCD （intensified charge coupled device） was adopted to shoot partially premixed flame image, and the exit temperature was tested with double platinum-rhodium thermocouple. At the same time, algorithms was developed for the directional selection of key characteristic parameters, spatio-temporal correlation decoupling, pulsation recognition, mean value calculation, maximum probability density distribution, etc. A dynamic flame characterization method was constructed. As shown, the lug turbulator was conducive to the forward lead of pulsating oscillation zone and conjugate temperature field, which strengthened the secondary atomization of fuel in the main reflux zone, and enhanced the multi-direction propagation of flame. Lug turbulators improved the flame stability and the uniformity of outlet temperature distribution under the premise of not significantly increasing the flow resistance. The wedge lug increased the flame expansion ratio by 5.2%—29.4%, while the triangle lug increased the combustion chamber outlet temperature by more than 40 K under the same inlet conditions to achieve the purpose of improving combustion efficiency.