Numerical Study On Combustion In-stability In The LDI Combustor

This paper mainly studies the combustion process in a turbine by numerical simula-tion, especially focuses on the production and emission of NOx·1) Establish a3D model of lean direct injection (LDI) combustion chamber, and mesh the model using ICEM.2) LES was applied in FLUENT with non-premixed combustion model, discrete phase model (DPM), mixture fraction/PDF equilibrium chemistry model and WALE subgrid-scale model to study the combustion of kerosene and air in a Lean Direct In-jection (LDI) combustor.3) The results are little different from that of experimental measurements in the areas near the injection, while they agree well with the experimental results in the other areas.4) The combustion became unstable while the inlet air velocity changed, and both in stable and unstable combustion processes, NOx emissions were calculated. The re-sults mean that combustion instability should be induced by disturbance of equiva-lence ratio, and that combustion instability can have an obvious effect on production and emission of NOx. It is feasible to control production and emission of NOx by us-ing oscillation combustion.