Large Eddy Simulations of Transverse Combustion Instability in a Multi-element Injector

Large Eddy Simulation (LES) is applied to study transverse combustion instability in a seven element combustor. The combustor is a self-excited linear array of seven elements. Different levels of instability are produced by changing which injectors flow fuel. Two configurations were analyzed, the most stable and the most unstable experimental configuration. The simulations showed different behavior for each case. For the unstable case, the simulated amplitudes were lower than the experimental, and there was nota well-defined transverse wave present in the combustor. Interestingly in this case the center element coupled with the first mode in the combustor and appeared to have a stabilizing effect. The amplitude of the simulated stable case was larger than the experimental, but showed evidence of a transverse instability.