Flow field and flame response characteristics of stratified swirl flame with external excitation
To study the feedback of shear swirl and flame and its induced combustion instability mechanism in the lean direct injection(LDI)combustor,the dynamic response of flow field and flame excited with external excitation was studied by large eddy simulation(LES)combined with phase space reconstruction and modal decomposition.Comparing the experimental results of the flow field with the time averaged results of LES,it was found that the velocity distribution of the numerical calculation and the size and position of the vortex structure were in good agreement with the experimental results.The analysis of LES acquisition signal and instantaneous flow field showed that the pressure and heat release pulsation were in the limit cycle oscillation state.The contraction and expansion of the recirculation zone under velocity pulsation led to the periodic compression and relaxation of the fuel and heat release zone,resulting in quasi-periodic heat release pulsation.The modal decomposition of the data on the meridian plane showed that the velocity and heat release pulsation were mainly concentrated in the shear layer and the jet region.Meanwhile,the main pulsation modes were all longitudinal pulsations excited by the inlet velocity.
excitationstratified swirllean direct injectionlarge eddy simulationphase space reconstructionmodal decomposition
NETL
NSTL
万方数据
